4:71 O you who have believed, take your precaution and [either] go forth in companies or go forth all together.
4:72 And indeed, there is among you he who lingers behind; and if disaster strikes you, he says,” Allah has favored me in that I was not present with them.”
4:74 So let those fight in the cause of Allah who sell the life of this world for the Hereafter. And he who fights in the cause of Allah and is killed or achieves victory – We will bestow upon him a great reward.
4:75 And what is [the matter] with you that you fight not in the cause of God and [for] the oppressed among men, women, and children who say, “Our Lord, take us out of this city of oppressive people and appoint for us from Yourself a protector and appoint for us from Yourself a helper?”
4:76 Those who believe fight in the cause of God, and those who disbelieve fight in the cause of Taghut. So fight against the allies of Satan. Indeed, the plot of Satan has ever been weak.
4:77 Have you not seen those who were told, “Restrain your hands [from fighting] and establish prayer and give zakah”? But then when fighting was ordained for them, at once a party of them feared men as they fear God or with [even] greater fear. They said, “Our Lord, why have You decreed upon us fighting? If only You had postponed [it for] us for a short time.” Say, The enjoyment of this world is little, and the Hereafter is better for he who fears God. And injustice will not be done to you, [even] as much as a thread [inside a date seed].”
4:71 The verse says to Muslims 1400 years ago to take precaution to either go in small groups or go all together. From the verse it hints that there was imminent danger for such verse to be revealed telling them to go in small groups, or all together.
4:74 Speaks about those who fight in the cause of God for defending the persecuted, 1400 years ago, will achieve victory. The victory here is that the person will be rewarded with Paradise which he shall abide in forever.
In Quran 4:75 we have explicit statement that the fighting in God’s cause was in defence of the persecuted, men, women and children who have been oppressed by tyrants just for their beliefs. Here we are told, questions those why shouldn’t they fight when they have been oppressed and continually persecuted?
In 4:76 we are told that there are two camps, one is fighting in God’s cause in defending humans from being oppressed and the other is fighting for satan. The camp of Satan is to spread evil, corruption, and misery on earth.
In the last verse (4:77), it speaks about those Muslims who used to make up excuses in not defending the Muslims, 1400 years ago. In reality they feared the enemy more than God.
Malik Ghulam Farid:
“630. Hidhr means, caution or precaution; vigilance; guard; state of preparation; or of fear (Lane). The word extends to all kinds of precautions and preparations necessary for defence, and has been understood to include the putting on of weapons of defence.
631. Al-Thubah means, a company or body of men; a distinct body or company of men; a troop of horsemen (Lane).
632. The verse refers to hypocrites or the internal enemies of Islam and mentions their two prominent traits.
632A. The words also mean, what is the matter with you that you fight not.
633. The verse is a clear proof of the fact that Muslims never started hostilities. They only fought in self-defence in order to protect their religion and save their weaker co-religionists.
634. The verse refers to a class of men who show eagerness to fight when they are told not to fight, but when the actual time for fighting arrives, they refuse to fight or try to avoid it by various pretexts, thus showing that their former eagerness for fighting was either insincere or was due to temporary excitement. ” 
“87 Lit., “and then go forth, [be it] in small detachments or all together”- the latter expression applying to what nowadays is called “total war”. The term hidhr connotes not merely an effort to guard oneself against imminent danger but also the making of all necessary preparations with regard to (in this context) military organization, equipment, etc. The problem of war as such arises from the principles of ideological statehood postulated in verse 59 of this surah. Since the Muslims are expected to organize their communal life within the framework of a state based on the ideological premises laid down in the Qur’an, they must be prepared for hostility on the part of groups or nations opposed to the world-view and the social system of Islam and, conceivably, bent on its destruction: consequently, the concept of a defensive war in God’s cause jihad) plays a very prominent role in the socio-political scheme of Islam and is frequently alluded to throughout the Qur’an.
88 Lit., “he”.
89 Lit., “what is amiss with you that you do not fight” – implying that they have no moral excuse for such a refusal.
90 Thus the Qur’an implies that “evil” is not an independent, esoteric factor of life, but rather a result of man’s succumbing to the temptations arising from his own moral weakness and thereby “denying the truth”. In other words, the “power” of the negative principle symbolized by Satan has no intrinsic reality (“Satan’s guile is weak indeed”): it becomes real only through man’s wilfully choosing a wrong course of action.
91 I.e., from unrighteous violence, to which man so often inclines. The fact that most people have to be told to refrain from violence is contrasted, in the next sentence, with the unwillingness on the part of many of them to expose themselves to physical danger in a righteous cause.” 
Tafsir Ibn Kathir:
“…Allah encouraged His believing servants to perform Jihad in His cause and to strive hard to save the oppressed Muslims in Makkah, men, women and children who were restless because of having to remain there. This is why Allah said, (whose cry is: “Our Lord! Rescue us from this town), referring to Makkah. In a similar Ayah, Allah said, (And many a town, stronger than your town which has driven you out) Allah then describes this town, (whose people are oppressors; and raise for us from You one who will protect, and raise for us from You one who will help) meaning, send protectors and helpers for us. Al-Bukhari recorded that Ibn `Abbas said, “I and my mother were from the oppressed (in Makkah).” Allah then said, (Those who believe, fight in the cause of Allah, and those who disbelieve, fight in the cause of the Taghut.) Therefore, the believers fight in obedience to Allah and to gain His pleasure, while the disbelievers fight in obedience to Shaytan. Allah then encourages the believers to fight His enemies, (So fight against the friends of Shaytan; ever feeble indeed is the plot of Shaytan).” 
Don’t forget to follow Discover The Truth on Facebook and Twitter. PLEASE help spread the word by sharing our articles on your favourite social networks.
 The Holy Qur’an – Arabic Text With English Translation & Short Commentary By Malik Ghulam Farid, Page 204 – 205
 The Message of The Quran translated and explained by Muhammad Asad, page 181 – 182
 Tafsir Ibn Kathir http://www.alim.org/library/quran/AlQuran-tafsir/TIK/4/75