"To the chief Musician, A Psalm of David, when Nathan the prophet (a) came unto him, after he had gone in to Bathsheba." Have mercy upon me, O God, (b) according to thy lovingkindness: according unto the multitude of thy tender mercies blot out my transgressions.
(a) To reprove him, because he had committed horrible sins, and lain in the same without repentance more then a whole year.
(b) As his sins were many and great, so he requires that God would give him the feeling of his excellent and abundant mercies.