The word(s) "backs" appears 26 time(s) in 26 verse(s) in Quran in Mohsin Khan translation.

(11) He said: "O my people! Is then my family of more weight with you than Allah? And you have cast Him away behind your backs. Verily, my Lord is surrounding all that you do.

(12) And We have put coverings over their hearts lest they should understand it (the Qur'an), and in their ears deafness. And when you make mention of your Lord Alone [La ilaha illallah (none has the right to be worshipped but Allah) Islamic Monotheism (توحيد الله)] in the Qur'an, they turn on their backs, fleeing in extreme dislike.

(13) If only those who disbelieved knew (the time) when they will not be able to ward off the Fire from their faces, nor from their backs, and they will not be helped.

(14) "And by Allah, I shall plot a plan (to destroy) your idols after you have gone away and turned your backs."

(15) Verily, you cannot make the dead to hear nor can you make the deaf to hear the call (i.e. benefit them and similarly the disbelievers), when they flee, turning their backs.

(16) So verily, you (O Muhammad صلى الله عليه وسلم) cannot make the dead to hear (i.e. the disbelievers), nor can you make the deaf to hear the call, when they show their backs and turn away.

(17) Allah has not made for any man two hearts inside his body. Neither has He made your wives whom you declare to be like your mothers' backs, your real mothers. [az-Zihar is the saying of a husband to his wife, "You are to me like the back of my mother" i.e. You are unlawful for me to approach], nor has He made your adopted sons your real sons. That is but your saying with your mouths. But Allah says the truth, and He guides to the (Right) Way.

(18) And indeed they had already made a covenant with Allah not to turn their backs, and a covenant with Allah must be answered for.

(19) Among the believers are men who have been true to their covenant with Allah [i.e. they have gone out for Jihad (holy fighting), and showed not their backs to the disbelievers]; of them some have fulfilled their obligations (i.e. have been martyred); and some of them are still waiting, but they have never changed [i.e. they never proved treacherous to their covenant which they concluded with Allah] in the least.

(20) A Day when you will turn your backs and flee having no protector from Allah. And whomsoever Allah sends astray, for him there is no guide.