Isaac, the miracle son of promise because of Abraham and Sarah’s faith, and his wife Rebekah conceived twins, Jacob and Esau. Rebekah was Isaac’s legitimate wife and not a foreign handmaid like Hagar. Both sons were legitimate, and not only legitimate but were the result of the same act of sexual intercourse. Paul wanted to be very clear about this. Two legitimate sons came from this one act of procreation between Isaac and Rebekah, but the covenant God made with Abraham and affirmed with the son of promise, Isaac, he established with only one son, Jacob. Why?