Genesis 25:20-26

When he was forty, he married Rebekah. She was the daughter of Bethuel and the sister of Laban. Both her father and brother were Arameans from Paddan-Aram. Now, Rebekah was unable to have children, but Isaac pleaded with YAHWEH on behalf of his wife because she was barren—and she did get pregnant, for YAHWEH responded to Isaac’s prayer. During her pregnancy, Rebekah could feel twins thrashing and struggling with each other inside her womb. So she went to inquire of YAHWEH, saying, “Why do I have to live with this?” And YAHWEH answered her, saying, “The two sons in your womb will become two nations, and the two peoples within you will become rivals. One people will become stronger than the other, and the older will serve the younger.” And when the time came for Rebekah to give birth, sure enough, she had twins! The first one came out reddish and covered with hair like a hairy garment; so they named him Esau. And his brother came out with his hand grasping Esau’s heel; so, they named him Jacob. Isaac was sixty when the twins were born.