1 Kings 11:14-16

14Then the Lord raised up Hadad the Edomite, a member of Edom’s royal family, to be Solomon’s adversary.

15Years before, David had defeated Edom. Joab, his army commander, had stayed to bury some of the Israelite soldiers who had died in battle. While there, they killed every male in Edom.

16Joab and the army of Israel had stayed there for six months, killing them.