Genesis 17:15-19

15Then God said to Abraham, “As for your wife Sarai, you shall not call her by the name 1Sarai, but 2Sarah shall be her name.

16I will bless her, and indeed I will give you 3a son by her. Then I will bless her, and she shall be a mother of nations; 4kings of peoples will 5come from her.”

17Then Abraham 6fell on his face and laughed, and said in his heart, “Will a child be born to a man a hundred years old? And 7will 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 8a son, and you shall name him 9Isaac; and 10I will establish My covenant with him as an everlasting covenant for his 11descendants after him.