19. And God said to Abraham: "Your wife Sarah shall give birth to a son, and you shall call his name Isaac, and I will establish my covenant with him as a perpetual covenant, and with his offspring after him.
20. Likewise, concerning Ishmael, I have heard you. Behold, I will bless and enlarge him, and I will multiply him greatly. He will produce twelve leaders, and I will make him into a great nation.
21. Yet in truth, I will establish my covenant with Isaac, to whom Sarah will give birth for you at this time next year."