The word(s) "back" appears 101 time(s) in 98 verse(s) in Quran in Muhammad Pickthal translation.

(51) Then Moses went back unto his folk, angry and sad. He said: O my people! Hath not your Lord promised you a fair promise? Did the time appointed then appear too long for you, or did ye wish that wrath from your Lord should come upon you, that ye broke tryst with me?

(52) He (Moses) said: O Aaron! What held thee back when thou didst see them gone astray,

(53) If those who disbelieved but knew the time when they will not be able to drive off the fire from their faces and from their backs, and they will not be helped!

(54) And, by Allah, I shall circumvent your idols after ye have gone away and turned your backs.

(55) O mankind! if ye are in doubt concerning the Resurrection, then lo! We have created you from dust, then from a drop of seed, then from a clot, then from a little lump of flesh shapely and shapeless, that We may make (it) clear for you. And We cause what We will to remain in the wombs for an appointed time, and afterward We bring you forth as infants, then (give you growth) that ye attain your full strength. And among you there is he who dieth (young), and among you there is he who is brought back to the most abject time of life, so that, after knowledge, he knoweth naught. And thou (Muhammad) seest the earth barren, but when We send down water thereon, it doth thrill and swell and put forth every lovely kind (of growth).

(56) Whenever, in their anguish, they would go forth from thence they are driven back therein and (it is said unto them): Taste the doom of burning.

(57) Hast thou not seen how Allah hath made all that is in the earth subservient unto you? And the ship runneth upon the sea by His command, and He holdeth back the heaven from falling on the earth unless by His leave. Lo! Allah is, for mankind, Full of Pity, Merciful.

(58) My revelations were recited unto you, but ye used to turn back on your heels,

(59) Until, when death cometh unto one of them, he saith: My Lord! Send me back,

(60) And We inspired the mother of Moses, saying: Suckle him and, when thou fearest for him, then cast him into the river and fear not nor grieve. Lo! We shall bring him back unto thee and shall make him (one) of Our messengers.