Translation:

30. As to those who believe and work righteousness verily We shall not suffer to perish the reward of any who do a (single) righteous deed.

Notes (Tafseer)

2372. The righteous will be rewarded, as has been said again and again, beyond their merits: xxviii. 84: xxx. 39. Not a single good deed of theirs will lose its reward, and the mercy of Allah will blot out their sins.