Genesis 17:20-22

20And as for Ishmael, I have heard you: I will surely bless him; I will make him fruitful and will greatly increase his numbers. He will be the father of twelve rulers, and I will make him into a great nation. 21But my covenant I will establish with Isaac, whom Sarah will bear to you by this time next year.”

22When he had finished speaking with Abraham, God went up from him.