The word(s) "back" appears 225 time(s) in 216 verse(s) in Quran in Abdullah Yusuf Ali translation.

(151) And yet they had already covenanted with Allah not to turn their backs, and a covenant with Allah must (surely) be answered for.

(152) Verily Allah knows those among you who keep back (men) and those who say to their brethren, "Come along to us", but come not to the fight except for just a little while.

(153) And Allah turned back the Unbelievers for (all) their fury: no advantage did they gain; and enough is Allah for the believers in their fight. And Allah is full of Strength, able to enforce His Will.

(154) We bestowed Grace aforetime on David from ourselves: "O ye Mountains! Sing ye back the Praises of Allah with him! and ye birds (also)! And We made the iron soft for him;-

(155) Say: "The appointment to you is for a Day, which ye cannot put back for an hour nor put forward."

(156) The Unbelievers say: "We shall neither believe in this scripture nor in (any) that (came) before it." Couldst thou but see when the wrong-doers will be made to stand before their Lord, throwing back the word (of blame) on one another! Those who had been despised will say to the arrogant ones: "Had it not been for you, we should certainly have been believers!"

(157) The arrogant ones will say to those who had been despised: "Was it we who kept you back from Guidance after it reached you? Nay, rather, it was ye who transgressed.

(158) And if they reject thee, so were messengers rejected before thee: to Allah back for decision all affairs.

(159) If Allah were to punish men according to what they deserve. He would not leave on the back of the (earth) a single living creature: but He gives them respite for a stated Term: when their Term expires, verily Allah has in His sight all His Servants.

(160) "It would not be reasonable in me if I did not serve Him Who created me, and to Whom ye shall (all) be brought back.