Genesis 25:19-21

This is the account of the family of Isaac, the son of Abraham. When Isaac was forty years old, he married Rebekah, the daughter of Bethuel the Aramean from Paddan-aram and the sister of Laban the Aramean. Isaac pleaded with the LORD on behalf of his wife, because she was unable to have children. The LORD answered Isaac’s prayer, and Rebekah became pregnant with twins.