The word(s) "back" appears 101 time(s) in 98 verse(s) in Quran in Muhammad Pickthal translation.

(41) So when they went back to their father they said: O our father! The measure is denied us, so send with us our brother that we may obtain the measure, surely we will guard him well.

(42) He said: I will not send him with you till ye give me an undertaking in the name of Allah that ye will bring him back to me, unless ye are surrounded. And when they gave him their undertaking he said: Allah is the Warden over what we say.

(43) So travel with thy household in a portion of the night, and follow thou their backs. Let none of you turn round, but go whither ye are commanded.

(44) And Allah createth you, then causeth you to die, and among you is he who is brought back to the most abject stage of life, so that he knoweth nothing after (having had) knowledge. Lo! Allah is Knower, Powerful.

(45) And We place upon their hearts veils lest they should understand it, and in their ears a deafness; and when thou makest mention of thy Lord alone in the Qur'an, they turn their backs in aversion.

(46) Or some created thing that is yet greater in your thoughts! Then they will say: Who shall bring us back (to life). Say: He Who created you at the first. Then will they shake their heads at thee, and say: When will it be? Say: It will perhaps be soon;

(47) Say (unto them): If ye possessed the treasures of the mercy of my Lord, ye would surely hold them back for fear of spending, for man was ever grudging.

(48) For they, if they should come to know of you, will stone you or turn you back to their religion; then ye will never prosper.

(49) I think not that the Hour will ever come, and if indeed I am brought back unto my Lord I surely shall find better than this as a resort.

(50) He said: As for him who doeth wrong, we shall punish him, and then he will be brought back unto his Lord, Who will punish him with awful punishment!