The word(s) "behind" appears 53 time(s) in 52 verse(s) in Quran in Abdullah Yusuf Ali translation.

(21) For each (such person) there are (angels) in succession, before and behind him: They guard him by command of Allah. Allah does not change a people's lot unless they change what is in their hearts. But when (once) Allah willeth a people's punishment, there can be no turning it back, nor will they find, besides Him, any to protect.

(22) To Us are known those of you who hasten forward, and those who lag behind.

(23) "Except his wife, who, We have ascertained, will be among those who will lag behind."

(24) (The angels say:) "We descend not but by command of thy Lord: to Him belongeth what is before us and what is behind us, and what is between: and thy Lord never doth forget,-

(25) He knows what (appears to His creatures as) before or after or behind them: but they shall not compass it with their knowledge.

(26) He knows what is before them, and what is behind them, and they offer no intercession except for those who are acceptable, and they stand in awe and reverence of His (Glory).

(27) He knows what is before them and what is behind them: and to Allah go back all questions (for decision).

(28) Thereafter We drowned those who remained behind.

(29) Except an old woman who lingered behind.

(30) But We saved him and his family, except his wife; her We destined to be of those who lagged behind.