Charles H. Spurgeon on Psalms 19:12

The prophet saith, "Who can understand his own faults?" No man can, but God can; therefore reason after this manner, as Saint Bernard saith: I know and am known; I know but in part, but God knows me and knows me wholly; but what I know I know but in part. So the apostle reasons; "I know nothing of myself, yet am I not hereby justified."

Admit that thou keepest thyself so free, and renewest thy repentance so daily that thou knowest nothing by thyself, yet mark what the apostle adds further; "Notwithstanding, I do not judge myself; I am not hereby justified, but he that judges me is the Lord." This is the condition of all men; he that is infinite knows them; therefore they should not dare to judge themselves, but with the prophet David, in Psalm 19, entreat the Lord that he would cleanse them from their secret sins. —Richard Stock.