The word(s) "back" appears 262 time(s) in 241 verse(s) in Quran in Muhammad Habib Shakir translation.

(61) O you who believe! when you meet those who disbelieve marching for war, then turn not your backs to them.

(62) And whoever shall turn his back to them on that day-- unless he turn aside for the sake of fighting or withdraws to a company-- then he, indeed, becomes deserving of Allah's wrath, and his abode is hell; and an evil destination shall it be.

(63) If you demanded a judgment, the judgment has then indeed come to you; and if you desist, it will be better for you; and if you turn back (to fight), We (too) shall turn back, and your forces shall avail you nothing, though they may be many, and (know) that Allah is with the believers.

(64) O you who believe! obey Allah and His Apostle and do not turn back from Him while you hear.

(65) And if Allah had known any good in them He would have made them hear, and if He makes them hear they would turn back while they withdraw.

(66) And if they turn back, then know that Allah is your Patron; most excellent is the Patron and most excellent the Helper.

(67) And had you seen when the angels will cause to die those who disbelieve, smiting their faces and their backs, and (saying): Taste the punishment of burning.

(68) And if you fear treachery on the part of a people, then throw back to them on terms of equality; surely Allah does not love the treacherous.

(69) And prepare against them what force you can and horses tied at the frontier, to frighten thereby the enemy of Allah and your enemy and others besides them, whom you do not know (but) Allah knows them; and whatever thing you will spend in Allah's way, it will be paid back to you fully and you shall not be dealt with unjustly.

(70) And an announcement from Allah and His Apostle to the people on the day of the greater pilgrimage that Allah and His Apostle are free from liability to the idolaters; therefore if you repent, it will be better for you, and if you turn back, then know that you will not weaken Allah; and announce painful punishment to those who disbelieve.