Genesis 17:16-18

I will bless her and will surely give you a son by her. I will bless her so that she will be the mother of nations; kings of peoples will come from her.” Abraham fell facedown; he laughed and said to himself, “Will a son be born to a man a hundred years old? Will Sarah bear a child at the age of ninety?” And Abraham said to God, “If only Ishmael might live under your blessing!”