The word(s) "back" appears 262 time(s) in 241 verse(s) in Quran in Muhammad Habib Shakir translation.

(71) Except those of the idolaters with whom you made an agreement, then they have not failed you in anything and have not backed up any one against you, so fulfill their agreement to the end of their term; surely Allah loves those who are careful (of their duty).

(72) Certainly Allah helped you in many battlefields and on the day of Hunain, when your great numbers made you vain, but they availed you nothing and the earth became strait to you notwithstanding its spaciousness, then you turned back retreating.

(73) On the day when it shall be heated in the fire of hell, then their foreheads and their sides and their backs shall be branded with it; this is what you hoarded up for yourselves, therefore taste what you hoarded.

(74) And if they had intended to go forth, they would certainly have provided equipment for it, but Allah did not like their going forth, so He withheld them, and it was said (to them): Hold back with those who hold back.

(75) If good befalls you, it grieves them, and if hardship afflicts you, they say: Indeed we had taken care of our affair before; and they turn back and are glad.

(76) They swear by Allah that they did not speak, and certainly they did speak, the word of unbelief, and disbelieved after their Islam, and they had determined upon what they have not been able to effect, and they did not find fault except because Allah and His Apostle enriched them out of His grace; therefore if they repent, it will be good for them; and if they turn back, Allah will chastise them with a painful chastisement in this world and the hereafter, and they shall not have in the land any guardian or a helper.

(77) But when He gave them out of His grace, they became niggardly of it and they turned back and they withdrew.

(78) They who taunt those of the faithful who give their alms freely, and those who give to the extent of their earnings and scoff at them; Allah will pay them back their scoffing, and they shall have a painful chastisement.

(79) Therefore if Allah brings you back to a party of them and then they ask your permission to go forth, say: By no means shall you ever go forth with me and by no means shall you fight an enemy with me; surely you chose to sit the first time, therefore sit (now) with those who remain behind.

(80) Nor in those who when they came to you that you might carry them, you said: I cannot find that on which to carry you; they went back while their eyes overflowed with tears on account of grief for not finding that which they should spend.