The word(s) "back" appears 161 time(s) in 150 verse(s) in Quran in Mohsin Khan translation.

(81) And among mankind is he who worships Allah as it were, upon the edge (i.e. in doubt): if good befalls him, he is content therewith; but if a trial befalls him, he turns back on his face (i.e. reverts to disbelief after embracing Islam). He loses both this world and the Hereafter. That is the evident loss.

(82) Every time they seek to get away therefrom, from anguish, they will be driven back therein, and (it will be) said to them: "Taste the torment of burning!"

(83) Indeed My Verses used to be recited to you, but you used to turn back on your heels (denying them, and refusing with hatred to listen to them).

(84) And it is He Who has created you on the earth, and to Him you shall be gathered back.

(85) Until, when death comes to one of them (those who join partners with Allah), he says: "My Lord! Send me back,

(86) "Did you think that We had created you in play (without any purpose), and that you would not be brought back to Us?"

(87) And if you find no one therein, still, enter not until permission has been given. And if you are asked to go back, go back, for it is purer for you. And Allah is All-Knower of what you do.

(88) Certainly, to Allah belongs all that is in the heavens and the earth. Surely, He knows your condition and (He knows) the Day when they will be brought back to Him, then He will inform them of what they did. And Allah is All-Knower of everything.

(89) And the (faithful) slaves of the Most Gracious (Allah) are those who walk on the earth in humility and sedateness, and when the foolish address them (with bad words) they reply back with mild words of gentleness.

(90) Except those who believe (in the Oneness of Allah - Islamic Monotheism) and do righteous deeds, and remember Allah much, and vindicate themselves after they have been wronged [by replying back in poetry to the unjust poetry (which the pagan poets utter against the Muslims)]. And those who do wrong will come to know by what overturning they will be overturned.