https://www.btstories.com/selling-the-birthright/
After Sarah died, Abraham married a woman named Keturah. Together they had six sons. Years later, when Abraham knew he was going to die, he gave gifts to Keturah and her sons, and sent them away to the land of the East. He then gave everything he owned to Isaac.
Abraham died when he was 175 years old. Isaac and Ishmael buried him in the same cave where Sarah was buried.
