So the young man, even the young man the prophet, went to Ramothgilead.

Jamieson-Fausset-Brown Bible Commentary

4-6. So the young man . went to Ramoth-gilead-His ready undertaking of this delicate and hazardous mission was an eminent proof of his piety and obedience. The act of anointing being done through a commissioned prophet, was a divine intimation of his investiture with the sovereign power. But it was sometimes done long prior to the actual possession of the throne (1Sa 16:13); and, in like manner, the commission had, in this instance, been given also a long time before to Elijah [1Ki 19:16], who, for good reasons, left it in charge to Elisha; and he awaited God's time and command for executing it [Poole].

Matthew Henry's Concise Commentary

9:1-10 In these and the like events, we must acknowledge the secret working of God, disposing men to fulfil his purposes respecting them. Jehu was anointed king over Israel, by the Lord's special choice. The Lord still had a remnant of his people, and would yet preserve his worship among them. Of this Jehu was reminded. He was commanded to destroy the house of Ahab, and, as far as he acted in obedience to God, and upon right principles, he needed not to regard reproach or opposition. The murder of God's prophets is strongly noticed. Jezebel persisted in idolatry and enmity to Jehovah and his servants, and her iniquity was now full.