What does Psalm 51:7 mean?
Again, David pleads for cleansing. He asks the Lord to purge him with hyssop to make him clean and to wash him to make him whiter than snow. To purge meant to purify by removing a stain. Hyssop was a plant that the priests used in ceremonial cleansings. They dipped a bunch of hyssop in the blood of a sacrificial animal and then sprinkled the blood on the person who required cleansing. Leviticus 14:4–7 refers to the use of blood-dipped hyssop in sprinkling seven times the person who is to be cleansed of leprosy.David recognized that he would be whiter than snow if the Lord washed away his sin. In Isaiah 1:18 the Lord invited the sinful people of Judah to come to Him and reason with Him, promising, "Though your sins be as scarlet, they shall be as white as snow; though they are red like crimson, they shall become like wool." When Jesus washed His disciples' feet in the upper room, He told unwilling Peter he would have no share with Him unless He washed them (John 13:8).
Psalm 51:1–7 is David's plea for mercy and cleansing. He admits he has sinned against God. His approach to confession is to take God's attitude toward sin. He sees his sins as transgressions, iniquity, evil, and the result of his lifelong offensive nature. First John 1:9–10 corresponds to this passage by teaching believers to confess their sins—to agree with God's stance about those sins—with the promise of God's forgiveness and cleansing.
This psalm opens with David's plea to God to show him mercy. He asks God to blot out his transgressions, wash his iniquities, and cleanse him from sin. He admits his sinning was against God. He also confesses his human sin nature. David asks God to make him as white as snow by purging him with hyssop. He longs for joy to return to him, but knows he was suffering because God had turned away from him. He pleads with God for a clean heart and a right spirit. He does not want God to cast him aside and remove His Holy Spirit. David longs for a renewal of the joy of his salvation. If cleansing from sin occurred and joy returned to him, David would teach transgressors God's ways, and sinners would be converted. He promises near the end of the psalm to declare God's praise if God would forgive him. He knew it would be futile to offer a sacrifice to God, because God delights in a broken and contrite heart and not in sacrifices offered with an unrepentant heart. David closes the psalm with a prayer for God to bless Jerusalem.
