The word(s) "back" appears 102 time(s) in 100 verse(s) in Quran in Saheeh International translation.

(1) How can you disbelieve in Allah when you were lifeless and He brought you to life; then He will cause you to die, then He will bring you [back] to life, and then to Him you will be returned.

(2) Then, you are those [same ones who are] killing one another and evicting a party of your people from their homes, cooperating against them in sin and aggression. And if they come to you as captives, you ransom them, although their eviction was forbidden to you. So do you believe in part of the Scripture and disbelieve in part? Then what is the recompense for those who do that among you except disgrace in worldly life; and on the Day of Resurrection they will be sent back to the severest of punishment. And Allah is not unaware of what you do.

(3) And when a messenger from Allah came to them confirming that which was with them, a party of those who had been given the Scripture threw the Scripture of Allah behind their backs as if they did not know [what it contained].

(4) Many of the People of the Scripture wish they could turn you back to disbelief after you have believed, out of envy from themselves [even] after the truth has become clear to them. So pardon and overlook until Allah delivers His command. Indeed, Allah is over all things competent.

(5) And thus we have made you a just community that you will be witnesses over the people and the Messenger will be a witness over you. And We did not make the qiblah which you used to face except that We might make evident who would follow the Messenger from who would turn back on his heels. And indeed, it is difficult except for those whom Allah has guided. And never would Allah have caused you to lose your faith. Indeed Allah is, to the people, Kind and Merciful.

(6) They ask you, [O Muhammad], about the new moons. Say, "They are measurements of time for the people and for Hajj." And it is not righteousness to enter houses from the back, but righteousness is [in] one who fears Allah. And enter houses from their doors. And fear Allah that you may succeed.

(7) They ask you about the sacred month - about fighting therein. Say, "Fighting therein is great [sin], but averting [people] from the way of Allah and disbelief in Him and [preventing access to] al-Masjid al-Haram and the expulsion of its people therefrom are greater [evil] in the sight of Allah. And fitnah is greater than killing." And they will continue to fight you until they turn you back from your religion if they are able. And whoever of you reverts from his religion [to disbelief] and dies while he is a disbeliever - for those, their deeds have become worthless in this world and the Hereafter, and those are the companions of the Fire, they will abide therein eternally.

(8) Divorced women remain in waiting for three periods, and it is not lawful for them to conceal what Allah has created in their wombs if they believe in Allah and the Last Day. And their husbands have more right to take them back in this [period] if they want reconciliation. And due to the wives is similar to what is expected of them, according to what is reasonable. But the men have a degree over them [in responsibility and authority]. And Allah is Exalted in Might and Wise.

(9) O you who have believed, if you obey a party of those who were given the Scripture, they would turn you back, after your belief, [to being] unbelievers.

(10) They will not harm you except for [some] annoyance. And if they fight you, they will show you their backs; then they will not be aided.