And thou shalt smite the house of Ahab thy master
For Jehu was one of Ahab's captains, as he was now one of his son's, as appears from ( 2 Kings 9:25 ) , but this was to be no objection with him to the destroying of his house, as being an act of high treason, since he had an order for it from the King of kings, and Lord of lords; which otherwise would have seemed unlawful and criminal, and what follows will sufficiently vindicate the justice of God in it:
that I may avenge the blood of my servants the prophets, and the blood
of all the servants of the Lord, at the hand of Jezebel;
who killed the prophets of the Lord, and caused to be put to death Naboth the servant of the Lord, and now their blood was to be avenged on her and her son Joram, and all her family.