Albert Barnes Commentary Psalms 103:10

"He hath not dealt with us after our sins, Nor rewarded us after our iniquities." — Psalms 103:10 (ASV)

He has not dealt with us after our sins - All may say this, and this is a ground of thanksgiving and praise. It is a matter for which we should render unceasing praise that God has not done to us as our sins deserved. Who of us can fail to stand in awe and tremble when we think what God might have justly done to us; what sufferings He might have brought upon us, which would have been no more than we deserved; what pain of body, what distress of mind, what anguish of bereavement—what sorrow, danger, sickness, losses—we might have suffered before the point was reached where it could be said that we were suffering more than a holy and just God might properly inflict on us.

Nor rewarded us according to our iniquities - That is, He has not inflicted suffering on us that could be regarded in any proper sense as a just retribution for what we have done; or, so that it could properly be said that the one fairly measured the other.