David's Penitential Prayer.
To the chief musician, for public performance, as an open confession of David's sin before the whole congregation, showing that his repentance was of the right kind, a psalm of David, when Nathan, the prophet, came unto him, after he had gone in to Bathsheba, 2 Samuel 11, 12. For about one year after his terrible sin of adultery David had hardened his heart against repentance, although he had no rest in his conscience during this time, Psalms 32:3-4. It was when Nathan had thundered the accusation at David, "Thou art the man!" that the latter's resistance was broken and he confessed his sin. He received the word of absolution at once, but was constrained, as he realized the greatness of his transgression more and more, to plead with the Lord for His full mercy, as well as for the strength which would enable him to devote his whole life to the expiation of his guilt before men.
David's Plea for Mercy