Genesis 25:19-21

This is how the story of Isaac begins. He was the beloved son of Abraham and the successor of Abraham’s blessing. 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.