Genesis 25:1-6

Abraham had taken another wife, whose name was Keturah. She bore him Zimran, Jokshan, Medan, Midian, Ishbak and Shuah. Jokshan was the father of Sheba and Dedan; the descendants of Dedan were the Ashurites, the Letushites and the Leummites. The sons of Midian were Ephah, Epher, Hanok, Abida and Eldaah. All these were descendants of Keturah. Abraham left everything he owned to Isaac. But while he was still living, he gave gifts to the sons of his concubines and sent them away from his son Isaac to the land of the east.