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

(21) In order that you may mount on their backs, and then may remember the Favour of your Lord when you mount thereon, and say: "Glory to Him Who has subjected this to us, and we could never have it (by our efforts).

(22) Then how (will it be) when the angels will take their souls at death, smiting their faces and their backs?

(23) And if those who disbelieve fight against you, they certainly would have turned their backs; then they would have found neither a Wali (protector, guardian) nor a helper.

(24) Their multitude will be put to flight, and they will show their backs.

(25) Surely, if they (the Jews) are expelled, never will they (hypocrites) go out with them; and if they are attacked, they will never help them. And (even) if they do help them, they (hypocrites) will turn their backs, and they will not be victorious.

(26) Calling (all) such as turn their backs and turn away their faces (from Faith) [picking and swallowing them up from that great gathering of mankind on the Day of Resurrection just as a bird picks up a food-grain from the earth with its beak and swallows it up] (Tafsir Al-Qurtubi)