Ismael learns that in the house of Abraham, it doesn't pay to mock the matriarch, as he and his mother are cast out. Hereafter she was referred to as Sarah "Barracuda" for her take no prisoners approach to multiple marriage.
In other news, Isaac is born, grows up a bit, and then is taken by his father to become a human sacrifice. If I can recall the pastoral sermons of my youth, it is important to emphasize Abe's obedience and try to ignore Isaac's point of view. No matter how much mental anguish that might entail for a child to be tied up and placed on a sacrificial altar by his own father, and to see the gleaming blade as his father raises his hand to slice him open, the important thing is to remember that Abraham obeys the LORD without questioning Him or trying to haggle down the price to just an amputation or two. What happened to the guy who just a while ago negotiated down the price of sparing Sodom?
Either this is an historical tale about an actual schizo who followed the voices in his head, or else it is a fable intended to convey a moral lesson. If the latter, the lesson must be this: Obey your tyrant without hesitation, no matter how arbitrary and immoral his commands might seem to you.