7 Are you ashamed, O Emperor, to do that which the royal prophet David, the forefather of Christ, according to the flesh, did? To him it was told how the rich man who had many flocks seized and killed the poor man's one lamb, because of the arrival of his guest, and recognizing that he himself was being condemned in the tale, for that he himself had done it, he said: “I have sinned against the Lord.” Bear it, then, without impatience, O Emperor, if it be said to you: “You have done that which was spoken of to King David by the prophet.” For if you listen obediently to this, and say: “I have sinned against the Lord,” if you repeat those words of the royal prophet: “O come let us worship and fall down before Him, and mourn before the Lord our God, Who made us,” it shall be said to you also: “Since you repent, the Lord puts away your sin, and you shall not die.”
Source: Letters (New Advent)