Now therefore know and consider what you will do; for evil is determined against our master, and against all his house: for he is such a worthless fellow that one can't speak to him.
So Abigail is there pleading with David. Beautiful woman, has brought all of these things, and she is making good sense. "You know why should you avenge yourself. God will avenge you David. He's taken care of you, and so forgive the foolishness of this foolish man."