Genesis 17:1-4, 17-19

When Abram was ninety-nine years old, YAHWEH appeared to him again and said, “I am the God who is more than enough. Live your life in my presence and be blameless. I will confirm my covenant between me and you, and I will greatly multiply your descendants.” Then Abram fell on his face in awe before God, and God said to him, “I establish my covenant with you

Then Abraham laughed so hard he fell to the ground, saying to himself, “How in the world can a hundred-year-old man become a father? How can my wife Sarah get pregnant at ninety?” And then he spoke out loud: “O, that Ishmael might prosper with your blessing!” God said, “Listen to me. I promise that you and Sarah will have a son, and you will call him Isaac. I will confirm my everlasting covenant of love with him and his seed.