("leaving behind".) Son of Abraham and Keturah (Genesis 25:2; 1 Chronicles 1:32). From him sprang the N. Arabians. There is a valley "Sabak" related to the name. The Keturahites extended from the borders of Palestine to the Persian gulf. Ishbak, as his name implies, left behind his brethren, having gone forth first. His dwelling was probably far away toward the Persian gulf, and also reaching into the peninsula.