Genesis 17:16-19

16I will bless her, and indeed I will give you 1a son by her. Then I will bless her, and she shall be a mother of nations; 2kings of peoples will 3come from her.”

17Then Abraham 4fell on his face and laughed, and said in his heart, “Will a child be born to a man a hundred years old? And 5will Sarah, who is ninety years old, give birth to a child?”

18And Abraham said to God, “Oh that Ishmael might live before You!”

19But God said, “No, but your wife Sarah will bear you 6a son, and you shall name him 7Isaac; and 8I will establish My covenant with him as an everlasting covenant for his 9descendants after him.