Genesis 17:17-22

Abraham fell facedown. Then he laughed and said to himself, “Can a child be born to a hundred-year-old man? Can Sarah, a ninety-year-old woman, give birth?” So Abraham said to God, “If only Ishmael were acceptable to you!” But God said, “No. Your wife Sarah will bear you a son, and you will name him Isaac. I will confirm my covenant with him as a permanent covenant for his future offspring. As for Ishmael, I have heard you. I will certainly bless him; I will make him fruitful and will multiply him greatly. He will father twelve tribal leaders, and I will make him into a great nation. But I will confirm my covenant with Isaac, whom Sarah will bear to you at this time next year.” When he finished talking with him, God withdrew from Abraham.