Genesis 17:19, 21
Genesis 17:19 NASB1995
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 descendants after him.
Genesis 17:21 NASB1995
But My covenant I will establish with Isaac, whom Sarah will bear to you at this season next year.”