 | Have mercy on me, O God, according to your unfailing love; according to your great compassion blot out my transgressions. |
 | Have mercy upon me, O God, according to thy lovingkindness: according unto the multitude of thy tender mercies blot out my transgressions. |
 | Be gracious to me, O God, according to Your lovingkindness; According to the greatness of Your compassion blot out my transgressions. |
| Psalm 51:1 |
Commentary
David 's call for mercy is the only appropriate request for a confessing sinner. No sinner should ask for justice, for that would mean judgment and ruin. Mercy and forgiveness is God's gift to the confessing sinner. Even when the Lord forgives, He does not tarnish His just character: confessed sins are covered by the sacrifice of His perfect Son on the Cross (2 Cor. 5:21).
Radmacher, E. D., Allen, R. B., & House, H. W. (1999). Nelson's new illustrated Bible commentary (Ps 51:1-2). Nashville: T. Nelson Publishers.
What exactly was the sin to which David was admitting? The Bible tells us plainly that he committed adultery with Bathsheba, the wife of Uriah the Hittite, and that when she became pregnant David tried in vain to cover his sin, eventually engineering Uriah's death (2 Sam. 11). Yet Psalm 51 does not mention the adultery, and it only touches upon the murder (51:14). Instead, the main transgression confessed is, "Against You, You only have I sinned, and done this evil in Your sight" (51:4).
David was not evading responsibility for the sexual immorality and murder, but he recognized that ultimately sin is an offense against a holy, righteous God. Even when other people are hurt by our sins, it is God whose standards have been violated. Thus, while sinners owe apologies and restitution to people, they owe contrite confession to God. He alone is able to forgive sins (Mark 2:7).
Radmacher, E. D., Allen, R. B., & House, H. W. (1999). Nelson's new illustrated Bible commentary (Ps 51). Nashville: T. Nelson Publishers.