Charles Ellicott Commentary Psalms 18:20-23

"Jehovah hath rewarded me according to my righteousness; According to the cleanness of my hands hath he recompensed me. For I have kept the ways of Jehovah, And have not wickedly departed from my God. For all his ordinances were before me, And I put not away his statutes from me. I was also perfect with him, And I kept myself from mine iniquity." — Psalms 18:20-23 (ASV)

For this protestation of innocence, compare Psalms 7:17 and various passages in Job. Self-righteous pride and vindication of one’s character under calumny are very different things. If this refers to the nation at large, compare Numbers 23:21. Here, also, the text in Samuel offers one or two trifling variations from ours.