Genesis 17:16-20

16I will bless her, and moreover, I will give you a son by her. I will bless her, and she shall become nations; kings of peoples shall come from her."

17Then Abraham fell on his face and laughed and said to himself, "Shall a child be born to a man who is a hundred years old? Shall Sarah, who is ninety years old, bear a child?"

18And Abraham said to God, "Oh that Ishmael might live before you!"

19God said, "No, but Sarah your wife shall bear you a son, and you shall call his name Isaac. I will establish my covenant with him as an everlasting covenant for his offspring after him.

20As for Ishmael, I have heard you; behold, I have blessed him and will make him fruitful and multiply him greatly. He shall father twelve princes, and I will make him into a great nation.