What does Psalm 41:4 mean?

David began this psalm stating that God would protect and heal those who properly cared for "the poor." In this context, that includes all disadvantaged people, not merely those without resources. Part of that blessing included the concept of "healing" (Psalm 41:1–3). In verse 4, David applies this healing to sin and forgiveness. He admits his own errors and asks God to restore him. In the rest of the psalm, David expresses his struggles with enemies. He confidently declares that his enemies will not win, because of his assurance in God's forgiving redemption.

Psalm 66:18 explains that holding sin in one's heart blocks prayer from reaching the Lord. The psalmist declares: "If I had cherished iniquity in my heart, the Lord would not have listened." David knew his confession of sin would clear the blockage. The same result occurs in the experience of every Christian who confesses his sin to the Lord. First John 1:9 promises, "If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness."

David also knew he did not deserve forgiveness. He appealed to the Lord to be gracious to him. Divine grace is the Lord's act of giving to sinners what they do not deserve.