Genesis 25:1-5

Now Abraham took another wife, whose name was Keturah. She bore to him Zimran and Jokshan and Medan and Midian and Ishbak and Shuah. Jokshan became the father of Sheba and Dedan. And the sons of Dedan were Asshurim and Letushim and Leummim. The sons of Midian were Ephah and Epher and Hanoch and Abida and Eldaah. All these were the sons of Keturah. Now Abraham gave all that he had to Isaac