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 seed after him.
And He said, “I will surely return to you at this time next year; and behold, Sarah your wife will have a son.” And Sarah was listening at the tent door which was behind him.
And He gave him the covenant of circumcision; and so Abraham was the father of Isaac, and circumcised him on the eighth day; and Isaac was the father of Jacob, and Jacob of the twelve patriarchs.