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

(201) Say to those of the dwellers of the desert who were left behind: You shall soon be invited (to fight) against a people possessing mighty prowess; you will fight against them until they submit; then if you obey, Allah will grant you a good reward; and if you turn back as you turned back before, He will punish you with a painful punishment.

(202) There is no harm in the blind, nor is there any harm in the lame, nor is there any harm in the sick (if they do not go forth); and whoever obeys Allah and His Apostle, He will cause him to enter gardens beneath which rivers flow, and whoever turns back, He will punish him with a painful punishment.

(203) Allah promised you many acquisitions which you will take, then He hastened on this one for you and held back the hands of men from you, and that it may be a sign for the believers and that He may guide you on a right path.

(204) And if those who disbelieve fight with you, they would certainly turn (their) backs, then they would not find any protector or a helper.

(205) And He it is Who held back their hands from you and your hands from them in the valley of Mecca after He had given you victory over them; and Allah is Seeing what you do.

(206) O you who believe! avoid most of suspicion, for surely suspicion in some cases is a sin, and do not spy nor let some of you backbite others. Does one of you like to eat the flesh of his dead brother? But you abhor it; and be careful of (your duty to) Allah, surely Allah is Oft-returning (to mercy), Merciful.

(207) Then turn your back upon them for you are not to blame;

(208) Therefore turn aside from him who turns his back upon Our reminder and does not desire anything but this world's life.

(209) Have you then seen him who turns his back?

(210) So turn (your) back on them (for) the day when the inviter shall invite them to a hard task,