And God said, Nay, but Sarah thy wife shall bear thee a son; and thou shalt call his name Isaac: and I will establish my covenant with him for an everlasting covenant for his seed after him.
And God said unto Abraham, Let it not be grievous in thy sight because of the lad, and because of thy bondwoman; in all that Sarah saith unto thee, hearken unto her voice; for in Isaac shall thy seed be called.