Psalm 51:1-2

51:1 Have mercy on me, O God,
according to your steadfast love;
according to your abundant mercy
blot out my transgressions.

2 Wash me thoroughly from my iniquity,
and cleanse me from my sin!

Notice the David’s tri-fold description of his adulterous actions:

1. Transgressions
2. Iniquity
3. Sin

Now notice his tri-fold request for God’s merciful action:

1. Blot out
2. Wash me
3. Cleanse me