Psalms 50:4

But what shall we say concerning David, to whom such testimony was borne, and of whom God said, “I have found a man after Mine own heart, David the son of Jesse; and in everlasting mercy have I anointed him?” Yet this very man saith to God, “Have mercy on me, O Lord, according to Thy great mercy; and according to the multitude of Thy compassions, blot out my transgression. Wash me still more from mine iniquity, and cleanse me from my sin. For I acknowledge my iniquity, and my sin is ever before me. Against Thee only have I sinned, and done that which was evil in Thy sight; that Thou mayest be justified in Thy sayings, and mayest overcome when Thou art judged. For, behold, I was conceived in transgressions, and in my sins did my mother conceive me. For, behold, Thou hast loved truth; the secret and hidden things of wisdom hast Thou shown me. …

“David too, of whom the Lord, testifying, says, ‘I found a man after my own heart, David the son of Jesse. With my holy oil I anointed him.’ But he also says to God, ‘Pity me, O God, according to Thy mercy; and according to the multitude of Thy tender mercies, blot out my transgression. Wash me thoroughly from mine iniquity, and cleanse me from my sin. For I know my transgression, and my sin is ever before me.’” Then, alluding to sin which is not subject to the law, in the exercise of the moderation of true knowledge, he adds, “Against Thee only have I sinned, and done evil in Thy sight.” For the Scripture somewhere says, “The Spirit of the Lord is a lamp, searching the recesses of the belly.” And the more of a Gnostic a man becomes by doing right, the nearer is the illuminating Spirit to him. …

But what shall we say concerning David, to whom such testimony was borne, and of whom God said, “I have found a man after mine own heart, David the son of Jesse; and in everlasting mercy have I anointed him?” Yet this very man saith to God, “Have mercy on me, O Lord, according to Thy great mercy; and according to the multitude of Thy compassions, blot out my transgression. Wash me still more from mine iniquity, and cleanse me from my sin. For I acknowledge mine iniquity, and my sin is ever before me. Against Thee only have I sinned, and done that which is evil in Thy sight; that Thou mayest be justified in Thy sayings, and mayest overcome when Thou art judged. For, behold, I was conceived in transgressions, and in sins did my mother conceive me. For, behold, Thou hast loved truth; the secret and hidden things of wisdom hast Thou shown me. …

7. “More and more wash me from mine unrighteousness” ( ver. 2 ). What is, “More and more wash”? One much stained. More and more wash the sins of one knowing. Thou that hast washed off the sins of one ignorant. Not even thus is it to be despaired of Thy mercy. “And from my delinquency purge Thou me.” According to the manner in which He is physician, offer a recompense. He is God, offer sacrifice. What wilt thou give that thou mayest be purged? For see upon whom thou callest; upon a Just One thou callest. He hateth sins, if He is just; He taketh vengeance upon sins, if He is just; thou wilt not be able to take away from the Lord God His justice: entreat mercy, but observe the justice: there is mercy to pardon the sinner, there is justice to punish the sin. …

The whole repentance of a sinner is exhibited to us in the fifty-first psalm written by David after he had gone in unto Bathsheba the wife of Uriah the Hittite, and when, to the rebuke of the prophet Nathan he had replied, “I have sinned.” Immediately that he confessed his fault he was comforted by the words: “the Lord also hath put away thy sin.” He had added murder to adultery; yet bursting into tears he says: “Have mercy upon me, O God, according to thy loving kindness: according unto the multitude of thy tender mercies blot out my transgressions.” A sin so great needed to find great mercy. Accordingly he goes on to say: “Wash me thoroughly from mine iniquity, and cleanse me from my sin. For I acknowledge my transgressions: and my sin is ever before me. …

4. What can show more pride than this, since the Scripture says: “No one is free from sin, not even an infant of a day old;” and David cries out: “Cleanse me from my sin.” Are they more holy than David, of whose family Christ vouchsafed to be born in the mystery of the Incarnation, whose descendant is that heavenly Hall which received the world’s Redeemer in her virgin womb? For what is more harsh than to inflict a penance which they do not relax, and by refusing pardon to take away the incentive to penance and repentance? Now no one can repent to good purpose unless he hopes for mercy.

38. The Lord said indeed to Mary Magdalene, “Touch Me not,” but He Who was pure did not say, “because I am pure.” Do you, Novatian, dare to call yourself pure, whilst, even if you were pure as regards your acts, you would be made impure by this saying alone? Isaiah says: “O wretched that I am, and pricked to the heart; for that being a man, and having unclean lips, I dwell also in the midst of a people having unclean lips,” and do you say, “I am clean,” when, as it is written, not even an infant of a day old is pure? David says, “And cleanse me from my sin,” whom for his tender heart the grace of God often cleansed; are you pure who are so unrighteous as to have no tenderness, as to see the mote in your brother’s eye, but not to consider the beam which is in your own eye? For with God no one who is unjust is pure. …