Tanach do Diwrej ha-jamim I 1:28

Avraham again took a wife. Her name was Keturah.

She bore him Zimran, Yokshon, Medan, Midian, Yishbok, and Shuach.

Yokshon fathered Shevah and Dedan. The sons of Dedan were Ashurim, Letushim and Leumim.