Now therefore, please let my lord the king hear the words of his servant. If it be Yahweh that has stirred you up against me, let him accept an offering: but if it be the children of men, cursed be they before Yahweh: for they have driven me out this day that I shouldn't cling to Yahweh's inheritance, saying, Go, serve other gods.
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."