Behold, as your life was much set by this day in my eyes, so let my life be much set by in the eyes of Yahweh, and let him deliver me out of all oppression.
So David is sort of chiding Abner the chief general of Saul, saying, "Hey you know your job is to guard the king, and you aren't doing a good job. You ought to be put to death. Someone came in to destroy the king, and you were just sound asleep. Look where the king's spear is, and the cruse of water."