What was the age of Rebecca when she was married off to Isaac? According to Rabbis in medieval history, she was no older than three 3-years-old. The Rabbis deduced this age number for Rebecca, from the Bible itself. A second early source, puts her age at 10.
Whenever Rabbi Rashi (or others) is quoted as saying that Rebecca was 3-years-old when she was married off, missionaries and other Christians dismiss this, and claim that this is only quoted from a man in the 11th century. There is no evidence that Rebecca was 3-years-old when married off in the Bible, they claim.
Even I, was surprised that Rashi, one of the most respected Rabbis would come to the conclusion that she was three, when married off to Isaac. This made me ask myself, why would an eminent scholar of such high calibre say that she was three when married off? Is there truth to what he is saying? This made me read, and reread the Genesis account, over and over again. Why did he came to the conclusion for her age at the time of her marriage? The clues he gave were the mount Moria incident with Isaac, and the time of Sarah’s death and her age.
We will endeavour to look into the account in Genesis a little closer, and see what appropriate age it gives for Rebecca when she was married off.
In order to find Rebecca’s age of marriage, we have to delve into the Bible itself. We are told that God had promised Sarah will bear a child, and he will be named Isaac:
“15 God also said to Abraham, “As for Sarai your wife, you are no longer to call her Sarai; her name will be Sarah. 16 I will bless her and will surely give you a son by her. I will bless her so that she will be the mother of nations; kings of peoples will come from her.”
17 Abraham fell facedown; he laughed and said to himself, “Will a son be born to a man a hundred years old? WILL SARAH BEAR A CHILD AT THE AGE OF NINETY?” 18 And Abraham said to God, “If only
Ishmael might live under your blessing!”
19 Then God said, “Yes, but your wife Sarah will bear you a son, and you will call him Isaac.[d] I will establish my covenant with him as an everlasting covenant for his descendants after him. 20 And as for Ishmael, I have heard you: I will surely bless him; I will make him fruitful and will greatly increase his numbers. He will be the father of twelve rulers, and I will make him into a great nation. 21 But my covenant I will establish with Isaac, whom SARAH WILL BEAR TO YOU BY THIS TIME NEXT YEAR.” 22 When he had finished speaking with Abraham, God went up from him.” – Genesis 17:15-22 (NIV)
The above text tells us that Sarah was around 90 or 91-years-old when she gave birth to Isaac. Sarah died at the age of 127, as Genesis 23 reports:
“The Death of Sarah
23 Sarah lived to be a hundred and twenty-seven years old. 2 She died at Kiriath Arba (that is, Hebron) in the land of Canaan, and Abraham went to mourn for Sarah and to weep over her.” – Genesis 23:1-2 (NIV)
Since Sarah gave birth to Isaac at 90 (or 91), Isaac would have been around 36 (or 37) when her mother had died.
This would mean that Isaac was 36 or 37-years-old when his father tried to sacrifice him on Mount Moria:
“22 Some time later God tested Abraham. He said to him, “Abraham!” “Here I am,” he replied. 2 Then God said, “Take your son, your only son, whom you love—Isaac—and go to the region of Moriah. Sacrifice him there as a burnt offering on a mountain I will show you.”
3 Early the next morning Abraham got up and loaded his donkey. He took with him two of his servants and his son Isaac. When he had cut enough wood for the burnt offering, he set out for the place God had told him about. 4 On the third day Abraham looked up and saw the place in the distance. 5 He said to his servants, “Stay here with the donkey while I and the boy go over there. We will worship and then we will come back to you.”6 Abraham took the wood for the burnt offering and placed it on his son Isaac, and he himself carried the fire and the knife. As the two of them went on together, 7 Isaac spoke up and said to his father Abraham, “Father?”
“Yes, my son?” Abraham replied.
“The fire and wood are here,” Isaac said, “but where is the lamb for the burnt offering?”
8 Abraham answered, “God himself will provide the lamb for the burnt offering, my son.” And the two of them went on together.
9 When they reached the place God had told him about, Abraham built an altar there and arranged the wood on it. He bound his son Isaac and laid him on the altar, on top of the wood. 10 Then he reached out his hand and took the knife to slay his son. 11 But the angel of the Lord called out to him from heaven, “Abraham! Abraham!”
“Here I am,” he replied.
12 “Do not lay a hand on the boy,” he said. “Do not do anything to him. Now I know that you fear God, because you have not withheld from me your son, your only son.”
13 Abraham looked up and there in a thicket he saw a ram[a] caught by its horns. He went over and took the ram and sacrificed it as a burnt offering instead of his son. 14 So Abraham called that place The Lord Will Provide. And to this day it is said, “On the mountain of the Lord it will be provided.” 15 The angel of the Lord called to Abraham from heaven a second time 16 and said, “I swear by myself, declares the Lord, that because you have done this and have not withheld your son, your only son, 17 I will surely bless you and make your descendants as numerous as the stars in the sky and as the sand on the seashore. Your descendants will take possession of the cities of their enemies, 18 and through your offspring[b] all nations on earth will be blessed,[c] because you have obeyed me.” 19 Then Abraham returned to his servants, and they set off together for Beersheba. And Abraham stayed in Beersheba.” – Genesis 22:19 (NIV)
This proves that Rebecca was born when Isaac was in his late 30s (37), just before the death of Sarah. Five verses down after Abraham and Isaac’s incident of sacrifice, we are told Rebecca was born:
“20 Some time later Abraham was told, “Milkah is also a mother; she has borne sons to your brother Nahor: 21 Uz the firstborn, Buz his brother, Kemuel (the father of Aram), 22 Kesed, Hazo, Pildash, Jidlaph and Bethuel.” 23 BETHUEL BECAME THE FATHER OF REBEKAH. Milkah bore these eight sons to Abraham’s brother Nahor. 24 His concubine, whose name was Reumah, also had sons: Tebah, Gaham, Tahash and Maakah.” – Genesis 22:20-24 (NIV)
Straight after the birth of Rebecca we find out the death of Sarah, when she was 127 years old:
“The Death of Sarah
23 Sarah lived to be a hundred and twenty-seven years old. 2 She died at Kiriath Arba (that is, Hebron) in the land of Canaan, and Abraham went to mourn for Sarah and to weep over her.” – Genesis 23:1-2 (NIV)
Some facts on what we have read so far:
1. Sarah gave birth to Isaac at the age of 90 (Genesis 17).
2. Sarah died at the age of 127 (Genesis 23:1-3)
3.The incident on Mount Moria (Genesis 22) and the birth of Rebecca happened at the same time, when Isaac was 36 (or 37) years old, same time when Sarah died (Genesis 23:1-3).
4. The verses all looked together tells us that Isaac was 37-years-old when Rebecca was born.
This fact that Isaac was sacrificed in his 30s is well attested by nearly all ancient sources and Rabbis .
Rabbi Shim’on said (2nd Century):
“Rabbi Shim’on said
“We have learned that the expression ‘And it came to pass in the days of denotes sorrow, while the expression ‘And it came to pass’ even with ‘in the days of’ is still tinged with sorrow.
‘And it came to pass after,’ after the lowest of all the higher spheres. Which is that? Devarim. As Moses said: ‘I am not a man of devarim’ (Exodus 4:10). And who came after this sphere? ’Elohiim tested Abraham.’ The Deviser of Evil came to accuse him in the presence of the Blessed Holy One. Here we must reflect:
‘Elohim tested Abraham.’ The verse should read: ‘tested Isaac,’ for ISAAC WAS ALREADY THIRTY-SEVEN YEARS OLD and his father was no longer responsible for him. If Isaac had said, ‘I refuse,’ his father would not have been punished. Why, then, is it written: ‘Elohim tested Abraham,’ and not ‘Isaac’?
(ZOHAR: The Book of Enlightenment [Translation and Introduction by Daniel Chanan Matt, Preface by Arthur Green, Paulist Press, 1983], page 71 – 72)
Genesis Rabba 55:4
“… Isaac retorted: ‘All that thou didst lend to the Holy One, blessed be He, was three drops of blood. But lo, I am now THIRTY-SEVEN YEARS OLD, yet if God desired of me that I be slaughtered, I would not refuse.’ Said the Holy One, blessed be He, ‘This is the moment!’ Straightway, God did prove Abraham.” (Midrash Rabbah, Translated Into English with notes, Glossary And Indices Under the Editorship of Rabbi Dr. H. Freedman, B. A., PH. D. And Maurice Simon, M. A., with a forward by Rabbi Dr. I. Epstein, B. A., PH.D., D.LIT. [The Soncino Press, London, Third Impression 1961, Printed in England by Stephen Austin And Sons, LTD., Hertford, Translated by Rabbi Dr. H. Freedman B.A., PH.D.], volume 1, page 485)
Rabbi Abraham Cohen De Herrera (1570 – 1635 AD):
“… On the other side, however, there is the quality of rigor and Justice, not spreading the influence of blessings, goodness, and life to any man unless, having tried him and proved him by singular means, it finds him worthy and just, going to the extreme lengths to which it subjected ISAAC, WHO WHEN HE WAS A YOUNG MAN OF 37 YEARS allowed himself to be bound by an old man of 137 and placed on the altar, stretched his neck toward his father’s lethal blade…” (Abraham Cohen De Herrera: Gate of Heaven – Translated from the Spanish with introduction and Notes by Kenneth Krabbenhoft (Tr.),[Koininklijke Brill, NV, Leiden, The Netherlands, 2002], page 56 – 57)
Rabbi Rashbam (1085 – 1158 AD):
“ויהי אחר הדברים האלה, whenever we find the construction אחר הדברים האלה what follows is conceptually immediately following what has been reported immediately before. Examples are found in 15,1 after Avraham had killed the four kings who had taken Lot captive. At that time G’d had told him not to be afraid of any repercussions. We also find such a construction in verse 20 of our chapter where the Avraham was informed of the birth of Rivkah after we heard that Yitzchok had been born. We find a similar construction also in Esther 3:1 where Mordechai told Esther and she told the king about the assassination plot by Bigtan and Teresh. The event occurred around the time when Haman was promoted and wanted to kill Mordechai and the Jewish people. The fact that he had saved the king’s life became the immediate cause of Mordechai’s rise in the king’s esteem. [if I understand the author correctly, he wants to tell us that although sequentially the matters related are not immediate chronologically, the Torah or Scriptures use the formulation to trace them to events which occurred some time back. YITZCHOK (ISAAC) WAS AT LEAST 37 YEARS OLD BEFORE AVRAHAM HEARD ABOUT THE BIRTH OF RIVKAH (REBECCA). Similarly, if the king had rewarded Mordechai for his part in discovering the plot immediately, history might have taken a different course. Ed.] Here too, the words mean that what follows occurred after Avraham and Avimelech had concluded their covenant according to which until the fourth generation Avraham’s descendants would not register a claim against lands owned by the Philistines at this time. G’d became very angry at this high-handed action by Avraham, seeing that he had given away lands which were part of what G’d had promised to Avraham and his descendants at the “covenant of the pieces” in chapter 15. We know that a condition of that covenant had been not to allow a single soul of the Canaanites to survive in that land, according to both Deuteronomy 20:16 as well as according to Joshua 13:3 and 15,45-47. Clearly lots had been cast concerning the lands owned by the 5 Philistine rulers, and who was to settle in those lands after the conquest. As a result of Avraham’s high-handed action. (Genesis 22:1 – Rabbi Rashbam, online source)
Targum Jonathan on Genesis 22:1
“And it was after these things that Izhak (Isaac) and Ishmael contended; and Ishmael said, It is right that I should inherit what is the father’s because I am his firstborn son. And Izhak (Isaac) said, It is right that I should inherit what is the father’s, because I am the son of Sarah his wife, and thou art the son of Hagar the handmaid of my mother. Ishmael answered and said, I am more righteous than thou, because I was circumcised at thirteen years; and if it had been my will to hinder, they should not have delivered me to be circumcised; but thou wast circumcised a child eight days; if thou hadst had knowledge, perhaps they should not have delivered thee to be circumcised. Izhak (Isaac) responded and said, Behold now, today I am thirty and six years old; and if the Holy One, blessed be He, were to require all my members, I would not delay. These words were heard before the Lord of the world, and the Word of the Lord at once tried Abraham, and said to him, Abraham! And he said, Behold me.(Targum Jonathan on Genesis 22:1, online source)
Cambridge Bible for Schools and Colleges:
“Jewish Tradition found a fertile subject in the ‘aḳêdah, or binding, of Isaac. The following passage from the Targum of Palestine is a good example of Haggadah (i.e. legend, or explanatory tradition): “And they came to the place of which the Lord had told him. And Abraham builded there the altar which Adam had built, which had been destroyed by the waters of the deluge, which Noah had again builded, and which had been destroyed in the age of divisions [i.e. the dispersion of the peoples]. And he set the wood in order upon it, and bound Isaac his son, and laid him on the altar upon the wood. And Abraham stretched out his hand, and took the knife to slay his son. And Isaac answered and said to his father, Bind me properly, lest I tremble from the affliction of my soul, and be cast into the pit of destruction, and there be found profaneness in thy offering. Now the eyes of Abraham looked on the eyes of Isaac; but the eyes of Isaac looked towards the angels on high, and Isaac beheld them, but Abraham saw them not. And the angels answered on high, Come, behold how these solitary ones who are in the world kill the one the other; he who slays delays not; he who is to be slain reacheth forth his neck. And the Angel of the Lord called to him, &c.”
“According to Jose ben Zimra, the idea of tempting Abraham was suggested by Satan who said, ‘Lord of the Universe! Here is a man whom thou hast blessed with a son at the age of one hundred years, and yet, amidst all his feasts, he did not offer thee a single dove or young pigeon for a sacrifice’ (Sanh. 87b; Gen. R. LV.). In Jose ben Zimra’s opinion, the ‘aḳedah took place immediately after Isaac’s weaning. This however is not the general opinion. According to the Rabbis, the ‘aḳedah not only coincided with, but was the cause of the death of Sarah, who was informed of Abraham’s intention while he and Isaac were on the way to Mount Moriah. THEREFORE ISAAC MUST THEN HAVE BEEN THIRTY-SEVEN YEARS OLD (Seder ‘Olam Rabbah, ed. Ratner, p. 6; Pirke R. El. XXXI.; Tanna debe Eliyahu R. XXVII.).” Jewish Encycl. s.v. Isaac.
“The Jews implore the mercy of God by the sacrifice of Isaac, as Christians by the sacrifice of Christ” (Mayor, Ep. James, p. 97). The merits of Isaac’s submission were regarded as abounding to the credit of the whole race; e.g. “For the merit of Isaac who offered himself upon the altar, the Holy One, blessed be He, will hereafter raise the dead” (Pesikta Rab. Kahana, p. 200, ed. Buber). Cambridge Bible for Schools and Colleges, online source)
Christian and non-Christian commentaries.
Adam Clarke commentary:
“…Rabbins that he was thirty-six; but IT IS MORE PROBABLE THAT HE WAS NOW ABOUT THIRTY-THREE, the age at which his great Antitype was offered up; and on this medium I have ventured to construct the chronology, of which I think it necessary to give this notice to the reader.” (The Holy Bible, Old And New Testaments. The Text. A Commentary And Critical Notes; Designed As a Help to a better Understand of the sacred writings: by Adam Clarke, LL. D. F.S.A., &c. The Old Testament. [New-YorkL Published By T. Mason & G. Lane, For The Methodist Episcopal Church, At The Conference Office, 200 Mulberry-Street. James Collord, Printer. 1837.], volume 1, (Genesis to Deuteronomy), page 138)
Coffman’s Commentaries on the Bible agrees with Adam Clarke’s statement on Isaac’s age:
“How old was Isaac at the time of this event? Some would make him only a little over three years of age, but the ability to carry an ass-load of wood up a mountain refutes that idea. Willis thought he was about twelve, but that is taken care of by the same load of wood. Keil thought he was a young man; and Kline thought he was a strong man. The answer given by Adam Clarke to this question is perceptive:
“Josephus supposed that Isaac was now twenty-five; some Rabbis say that he was thirty-six; but it is MORE PROBABLE THAT HE WAS ABOUT THIRTY-THREE, the age at which his great Antitype was offered up.”
WE BELIEVE THAT THIS CONCLUSION BY CLARKE IS TRUSTWORTHY. (Coffman’s Commentaries on the Bible, Genesis 22:5-6 – online source)
Thomas Coke Commentary on the Holy Bible:
“…Genesis 22:6. Abraham took the wood, and laid it upon Isaac— Hence it appears, among other circumstances, that Isaac must have been full-grown at this time. … It appears probable that he was more: there were about THIRTY-SEVEN YEARS from his birth to the death of Sarah; so that it is not unlikely, that in age, as well as in bearing the wood, on which he was to be sacrificed, he represented Christ, who bore his own cross, and was ABOVE THIRTY YEARS OLD. It is also observed, that Isaac, being of this age, must have voluntarily submitted to be bound and sacrificed by his father, as so old a man could not have had strength sufficient, had Isaac resisted. …” (Thomas Coke Commentary on the Holy Bible, Genesis 22:6 – online source)
Lange’s Commentary on the Holy Scriptures: Critical, Doctrinal, and Homiletical:
“Starke: (Moses does not relate the peculiar time of this severe test of Abraham’s faith. Some place it in the thirteenth, others in the fifteenth, and still others in the thirty-fifth or thirty-seventh year of Isaac. Because in this whole transaction Isaac was a type of Christ, and he finished the work of redemption, through his death, in the thirty-third, or according to others the THIRTY-FOURTH, YEAR OF HIS AGE, IT MAY WELL BE THOUGHT THAT IN THIS YEAR ALSO ISAAC WAS LED OUT AS A SACRIFICE.” (Lange’s Commentary on the Holy Scriptures: Critical, Doctrinal, and Homiletical – Genesis 22, online source)
Gospel scholar David J. Ridges:
“We must not overlook Isaac’s role in this test of faith. Isaac would have been strong and vigorous, probably INTO HIS THIRTIES at this time, while Abraham would have been quite elderly, unable to carry out this command of the Lord without Isaac’s willing cooperation. We will quote from the Old Testament student Manual on this:
‘Isaac voluntarily submitted to Abraham. This important parallel is often overlooked. The Old Testament does not give enough detail to indicate exactly how old Isaac was at the time of this event, but it is very likely that he was an adult. Immediately following the account of the sacrifice on Mount Moriah is recorded the statement that Sarah died at the age of 127 (see Genesis 23:1). THIS, ISAAC WOULD HAVE BEEN 37 at the time of her death. Even if the journey to Moriah had happened several years before Sarah’s, Isaac would have been in his thirties, as was the savior at the time of his crucifixion. …” (The Old Testament Made Easier, Part One: Genesis through Exodus 24 [second edition] by David J. Ridges, page 233)
Professor Jules Gleicher:
“VII. Arranging a Burial
Genesis 23:1 states that Sarah was 127 years old when died. According to Targum Yonasan, a rabbinical gloss from the second century CE, the fact that the account of Sarah’s death follows the Akedah indicates a causal connection – she died when Satan told her that Abraham had actually slaughtered Isaac (Scherman, p. 106). Sarah was ninety years old when she miraculously gave birth to Isaac (Gen. 17:17). This would make Isaac THIRTY-SEVEN at her death… It is more credible and very much less shocking to imagine a man in his thirties voluntarily submitting to be sacrificing than a mere boy or adolescent teenager.” (Political Themes in the Hebrew Scriptures [Palgrave Macmillan, 2010] by Jules Gleicher, page 41 – 42)
Associate Professor of history Alonzo L. Gaskill:
“As an example of how Isaac was a type for Christ, note that Isaac was the birthright son of a righteous father (see Genesis 21), as was Jesus (see D&C 93:21). Isaac’s birth required a miracle (see Genesis 11:30; 17:15-22), as did Jesus’ (see Luke 1:26-38). IN HIS MID-THIRTIES, ISAAC WAS OFFERED AS A SACRIFICE BY HIS FATHER. Jesus was offered up by the Father apparently sometimes during his thirty-fourth year of life. Genesis Rabbah 56:8 suggests that Isaac was somewhere between thirty-five and thirty-seven years of age; see also Victor P. Hamilton, Handbook on the Pentateuch (Grand Rapids, Michigan: Baker Book House, 1982), 108; Bruce R. McConkie, The Mortal Messiah (Salt Lake City: Deseret Book, 1979-81), 1: 364. …” (Temple Reflections: Insights into the House of the Lord [CFI, Cedar Fort, Inc, 2016] by Associate Professor of history Alonzo L. Gaskill, page 65)
Bruce R. McConkie (1915 – 1985):
“Abraham takes Isaac, his only begotten son, up upon Mount Moriah, there to sacrifice him at the Lord’s command; and Isaac, reputed by Jewish tradition to be thirty-seven years of age at the time, submits willingly to his father’s will-all as ‘a similitude of God and his Only Begotten Son’ [Jacob 4:5] (The Mortal Messiah, by Bruce R. McConkie Volume 1, page 364).
A New Chronology For Old Testament Times – Jan Van Tuyl:
“It seems that logically and mathematically, thirty-seven is the right one, and the proof follows here.
All texts agree that Isaac was born when Abraham was one hundred years (Gen 21:5; DSS: Q544; Ant. 1. 11. 1; Jas 21:1; Jub 15:17). All agree that Sarah was Isaac’s mother and that she was ten years younger than Abraham (Gen 16:16; Jub 15:17), so Sarah was ninety in the year Isaac was born. Sarah died of sorrow and a broken heart when she was sadistically and wrongly led to believe by Satan that Isaac had really been sacrificed and that of course he was now stone dead. Her age at death is readily found in the Bible: she passed away at the age of 127 years (Gen 23:1). The Book of jubilees shows that same age of 127 years (Jub 19:7). By just deducting the 90 from the 127, the correct age of 37 years for Isaac on the alter is found. By deducting these 37 years from his birth year (deducting and not adding, because this plays in the BC period, the exact time of the scene at the alter computes to be 1941 – 37 = 1904. That is the precise start year for the “about 450 years” countdown. (A New Chronology For Old Testament Times: With Solutions to Many Hitherto Unsolved Problems through the Use of Rare Texts [AuthorHouse 2012], by Jan Van Tuyl, page 222)
The above scholarly statements quite clearly coincide and agree that Isaac was in his thirties at the time of his sacrifice. Their conclusions in all, most cases, refer to Sarah’s death at 127 (in Genesis 23:1-2), as evidence of Isaac being 37 at the time of his sacrifice.
So what is the significance of Isaac’s age at the time of his sacrifice? Well, according to the Bible, Isaac was 37-years-old when he went up on Mount Moriah with his father. Rebecca was born straight after Isaac and Abraham, came down from the Mount Moriah and they went to Beersheba. Isaac was married to Rebecca when he was 40-years-old (Genesis 25:20). Since that is the case, this would mean Rebecca, was married off when she was 3 (or 4) years old. This would render Rabbi Rashi’s statement and others of Rebecca being 3-years-old when married to Isaac, as true when we look at Genesis account closely.
The following are two respected Rabbis statements who said that Rebecca was 3-years-old when she was married off. Rabbi Solomon Itzhaki (A.K.A. Rashi a well-known respected Jewish Scholar, 1040 – 1105 AD), comments on Rebecca’s age of marriage:
“1. Rashi’s commentary on Genesis 25:20 says: forty years old: For when Abraham came from Mount Moriah, he was informed that Rebecca had been born. Isaac was then thirty-seven years old, for at that time Sarah died, and from the time that Isaac was born until the “Binding” [of Isaac], when Sarah died, were thirty-seven years, for she was ninety years old when Isaac was born, and one hundred and twenty-seven when she died, as it is stated (above 23:1): “The life of Sarah was [a hundred and twenty-seven years.”] This makes Isaac thirty-seven years old, and at that time, Rebecca was born. HE WAITED FOR HER UNTIL SHE WOULD BE FIT FOR MARITAL RELATIONS-THREE YEARS-AND THEN MARRIED HER.— [From Gen. Rabbah 57:1] [Retrieved it from this website: http://www.chabad.org/library/bible_cdo/aid/8220/showrashi/true%5D
Rabbi Tobiah Ben Eliezer (1050 – 1108 AD) also confirms that she was 3-years-old when she was married to Isaac:
“Isaac was thirty-seven-years old at his binding… When Abraham returned from Mount Moriah, at that very moment Sarah died, and Isaac was then thirty-seven; and at that very time Abraham was told of Rebekah’s birth; THUS WE FIND THAT REBECCA WAS THREE YEARS OLD WHEN SHE MARRIED ISAAC.” (Pesikta Zutrata (Lekah Tov), Gen. 24., Midrashic commentary on the Pentateuch, by Rabbi Tobiah Ben Eliezer)
Rebecca’s young age is alluded too in Genesis 24:57-59. The following verse corroborates with the previous evidences shown that Rebekah, was a very young girl when she got married. She was so young that she needed a nursing woman with her when she was married off:
“Then they said, “Let’s call the young woman and ask her about it.” 58 So they called Rebekah and asked her, “Will you go with this man?” “I will go,” she said. 59 So they sent their sister REBEKAH ON HER WAY, ALONG WITH HER NURSE and Abraham’s servant and his men. 60 And they blessed Rebekah and said to her.” – Genesis 24:57-60
If Rebekah was a grown woman as some have assumed, who attained full womanhood, why would she need a ‘nursing woman’ to accompany her? This very verse shows she was very young and not at an age where she can take care of herself.
Although Rabbi Rashi and other scholars have said that Rebecca was 3-years-old when married, in line what the Bible says, I personally believe she was a bit older. The age most appropriate to assign to her, in line with historical evidence of girls being married off, is that she was below the age of 10-years old .
Looking at the Genesis account of when Isaac was born, the death of Sarah, and the incident on Mount Moriah, gives us evidence that Rebecca was born when Isaac was thirty-seven years old. This fact that he was in his thirties is supported not only from the Bible, majority of ancient Rabbis and Christian scholars have held this opinion also. Rebecca was born straight after the mount Moria incident, when Isaac was thirty-seven years old. Isaac married her when he was forty-years-old. This would mean, according to the Biblical narrative that she was three years old when she was given away in marriage to Isaac . The account in Genesis 24:57-60, states that she had a “nursing” woman with her when she was given away, this again supports the Bible and Rabbi Rashi’s statements in regards to the marriage, that she was three-years-old when the marriage took place.
An alternative in understanding this marriage without discarding and rejecting the Genesis account: There is a way (maybe) to understand this marriage, without it being as controversial as it seems. The marriage itself could have taken place, but Isaac may have waited for her to hit puberty or when she was ready for him cohabit with. Sometimes, in ancient times, marriages may have taken place, but the couple wouldn’t sleep with each other, until the other is ready and is matured. This might be the case here. For scripture tells us that Isaac was sixty years old when Rebecca gave birth to twins (Genesis 25:24-26). This would mean that Rebecca had her twins born twenty years after her marriage to Isaac.
 Rabbi Radak (1160 – 1235): states that Abraham was 137 years old when the incident of Mount Moriah occured. This would mean that Isaac was 37, given that Abraham had him when he was 100 years old:
“אשר אמר אליך, just as at the time when Avraham had been told to leave Charan and move to the Land of Canaan in 12,1 he had been told only to move to a country which G’d would specify later on. At that time Avraham had correctly assumed that he was to set out in the direction of the Land of Canaan. The absence of this detail in both instances was to show us the readers that instead of questioning G’d on details, Avraham set out to undertake difficult tasks without looking for any excuse to delay carrying out G’d’s instructions. It would have been so easy to ask G’d why, if he was to offer Yitzchok (Isaac) as a sacrifice, he first had to travel a long distance to the site where this was to take place. AFTER ALL, WE ARE SPEAKING ABOUT A MAN OF 137 YEARS OF AGE. Actually, if we do not err, G’d had two good reasons why He told Avraham what to do in such an ambivalent fashion. Firstly, to give Avraham additional credit for complying with a command which was wrapped in a riddle, without questioning G’d about it. If G’d had asked him to do this at once near his home, Avraham would not have had time to recover from the initial shock after hearing G’d’s instructions. If, after having had time to digest the implications of what had been asked of him, Avraham proceeded without hesitating, this is even more to his credit. The second reason why G’d worded the instructions in the manner in which the Torah records them, is to teach us that the site where this binding eventually took place is such a holy site; moreover after Avraham named the site, we know that it is one where the attribute of Justice may be changed to the attribute of Mercy due to the manner in which man relates to G’d’s commands. Not only that, but man learned that sometimes the intention behind an action is worth more to G’d than the action itself, so that the binding of Yitzchok (Isaac) rated in G’d’s eyes as if his father had actually sacrificed him.” (Rabbi Radak, commentary on Genesis 22:2, online source)
 A non-Biblical source, The book Jasher 22:53 says that she was 10-years-old when Rebecca was married off to Isaac:
“51 And now that his son Isaac is born to him, he has forsaken thee, he has made a great feast for all the inhabitants of the land, and the Lord he has forgotten.
52 For amidst all that he has done he brought thee no offering; neither burnt offering nor peace offering, neither ox, lamb nor goat of all that he killed on the day that his son was weaned.
53 Even from the time of his son’s birth till now, being thirty-seven years, he built no altar before thee, nor brought any offering to thee, for he saw that thou didst give what he requested before thee, and he therefore forsook thee.” – (The Book of Jasher Referred to in Joshua and Second Samuel Faithfully Translated FROM THE ORIGINAL HEBREW INTO ENGLISH, SALT LAKE CITY: PUBLISHED BY J.H. PARRY & COMPANY 1887. Book of Jasher 22:53, online source)
 Here is a in-direct quote on Isaac’s incident with Abraham on Mount Moriah, that he was thirty-seven years old. Joseph Ibn Kaspi (1280 Arles—1345 Majorca):
“Yitzhak (Isaac) remained on Mount Moriah for three years until he reached the age of forty, & then he married Rivkah (Rebekah).” (Joseph Ibn Kaspi, Mishneh Kesef on the Torah, volume 2, page 63))
America’s Child-Marriage Problem (NYTimes.com)
Child marriage chart reveals girls can wed at 12 in some parts of the US (Independent.co.uk)