Genesis 17:19

God said, “No, not Ishmael. Listen, your wife Sarah will have a baby boy. He will be your son, and you will call him Isaac .” (That name Isaac means laugh .) And God said, “He will be the son I’m talking about. I will keep this agreement going with him. It will be the same for him, and for all the people that will be born into his family later on. This agreement will go on for ever.