David’s Psalm 51: A Prayer of Repentance

“Have mercy upon me, O God,
According to Your lovingkindness;
According to the multitude of Your tender mercies,
Blot out my transgressions.
Wash me thoroughly from my iniquity,
And cleanse me from my sin.”
(Psalm 51:1-2)

This psalm was born out of a tragic story, that of David’s fall into gross sin. David had committed adultery and had a man murdered in order to cover it up. David’s friend Nathan confronted his sin. When that happened, God graciously worked a spirit of repentance in David’s heart, and raised him back up.

In the first few verses of Psalm 51, we have a glimpse of David’s prayer of repentance. 

What kind of prayer was it?

It was a prayer of humble confession: “Have mercy upon me, O God… Blot out my transgressions. Wash me thoroughly from my iniquity.” In fact, David’s prayer is very similar to the one Jesus put into the mouth of his penitent publican in the parable: “God, be merciful to me a sinner!” (Luke 18:13).

What was the prayer for?

It was a prayer for mercy. Upon many accounts, David was a man of great deeds. Not only had he done much, but he had suffered much in the service of God. Yet, when he is finally convinced of his own sin, he doesn’t try to balance out his evil deeds with good deeds. Instead, he flies to God’s infinite mercy as his only pardon and peace: “Have mercy upon me, O God!”

It was mercy not according to the dignity of his birth, his descending from Judah, his public services as Israel’s champion, or his honor as Israel’s king. It was a plea for mercy for mercy’s sake. “Have mercy upon me, O God, according to Your lovingkindness,” is what we prays.

Why was mercy sought?

The particular mercy that David begs for is the pardon of sin. “Blot out my transgressions,” was his prayer. Blot them out as a debt is blotted from an accounting book. The blood of Christ, sprinkled upon the conscience, to purify and pacify that, blots out sin’s transgression and reconciles us to God. “Cleanse me from my sin,” David says, because he knows that sin defiles us and renders us repulsive in the sight of a holy God; it disqualifies us from enjoying communion with God.

When God pardons sin, he cleanses us from it so that we can become acceptable and pleasing to Him, so that we can know Him, so that we can have access to Him.

At the point of repentance, David had a keen awareness of his sin’s folly, his need for grace, and his God’s willingness to show mercy according to divine lovingkindness. May we have the same awareness today.

(This outline was adapted from Matthew Henry’s classic Bible commentary, available at Blue Letter Bible)