Genesis 17:1-4, 17-19

Now when Abram was ninety-nine years old, the LORD appeared to Abram and said to him, “I am God Almighty; Walk before Me, and be blameless. I will establish My covenant between Me and you, And I will multiply you exceedingly.” Abram fell on his face, and God talked with him, saying, “As for Me, behold, My covenant is with you, And you will be the father of a multitude of nations.

Then Abraham fell on his face and laughed, and said in his heart, “Will a child be born to a man one hundred years old? And will Sarah, who is ninety years old, bear a child?” And Abraham said to God, “Oh that Ishmael might live before You!” But God said, “No, but Sarah your wife will bear you a son, and you shall call his name Isaac; and I will establish My covenant with him for an everlasting covenant for his descendants after him.