Charles Ellicott Commentary Proverbs 20:9

"Who can say, I have made my heart clean, I am pure from my sin?" — Proverbs 20:9 (ASV)

Who can say, I have made my heart clean? —Though we may have done our best by self-examination and confession, and repentance and trust in the atoning blood of Christ to obtain remission of sin, still the heart is so deceitful (Jeremiah 17:9), sins may so easily have escaped our notice (Psalms 19:12, 1 Corinthians 4:4), that satisfaction with ourselves ought never to be allowed (Romans 11:20).