1 Kings 11:13-16
English Standard Version
14And the Lord raised up an adversary against Solomon, Hadad the Edomite. He was of the royal house in Edom.
15For when David was in Edom, and Joab the commander of the army went up to bury the slain, he struck down every male in Edom
16(for Joab and all Israel remained there six months, until he had cut off every male in Edom).