How long was Rebekah barren before the twins were born?
Scripture records that Rebekah was barren for almost twenty years. Isaac was forty years old when he took her as wife, and he was sixty when the twins were finally born, so the period of barrenness lasted about two decades.
Les explains from Genesis 25:19-23 that Isaac was forty years old when he took Rebekah to wife, and she was barren. Isaac entreated the LORD for his wife because she was barren. Les points to the timeline on the board showing that Rebekah was barren for almost twenty years—from the time Isaac was forty until he was sixty, when the twins were finally born. The period of barrenness ended when the twins arrived at Isaac's age sixty.
And Isaac intreated the LORD for his wife, because she was barren: and the LORD was intreated of him, and Rebekah his wife conceived.