Surely Allah does not do injustice to the weight of an atom, and if it is a good deed He multiplies it and gives from Himself a great reward.

He it is Who created you from a single being, and of the same (kind) did He make his mate, that he might incline to her; so when he covers her she bears a light burden, then moves about with it; but when it grows heavy, they both call upon Allah, their Lord: If Thou givest us a good one, we shall certainly be of the grateful ones.

And We will set up a just balance on the day of resurrection, so no soul shall be dealt with unjustly in the least; and though there be the weight of a grain of mustard seed, (yet) will We bring it, and sufficient are We to take account.

O my son! surely if it is the very weight of the grain of a mustard-seed, even though it is in (the heart of) rock, or (high above) in the heaven or (deep down) in the earth, Allah will bring it (to light); surely Allah is Knower of subtleties, Aware;