1 Kings 11:14 - Coke's Commentary on the Holy Bible

Hadad the Edomite— Hadad was a young prince of the royal family of Idumea, who fled into Egypt when David conquered that country: for David, having obtained a signal victory under the conduct of Abishai, who, at that time commanded in chief, sent Joab afterwards with an order to kill all the males who should be found in the land. But Hadad had escaped into Egypt, where, finding favour with the king, he married his wife's sister, and there settled.