1 Kings 11:14-17

14Then the Lord stirred up an adversary against Solomon, Hadad the Edomite; he was of royal descent in Edom.

15For it came about, when David was in Edom, and Joab the commander of the army had gone up to bury those killed [in battle] and had struck down every male in Edom

16(for Joab and all [the army of] Israel stayed there six months, until he had killed every male in Edom),

17that Hadad escaped to Egypt, he and some Edomites from his father’s servants with him, while Hadad was [still] a little boy.