God sent an angel to Jerusalem to destroy it: and as he was about to destroy, Yahweh saw, and he repented him of the evil, and said to the destroying angel, It is enough; now stay your hand. The angel of Yahweh was standing by the threshing floor of Ornan the Jebusite.
"Perhaps the one thing that impresses more than David’s sins in his life are his repentances (cf. 2 Samuel 12:13 ff., and, associated in its heading with the same incident, Psalms 51). We do well to let his willingness to come fully to terms with his deficiencies inform our own responses to our moral failures before God." [Note: McConville, p. 71.] 