Matthew Henry on 2 Kings 9:1-10
We have here the anointing of Jehu to be king, who was, at this time, a commander (probably commander-in-chief) of the forces employed at Ramoth-Gilead, Kg2 9:14. There he was fighting for the king his master, but received orders from a higher king to fight against him. It does not appear that Jehu aimed at the government, or that he ever thought of it, but the commission given him was a perfect surprise to him. Some think that he had been anointed before by Elijah, whom God ordered to do it, but privately, and with an intimation that he must not act till further orders, as Samuel anointed David long before he was to come to the throne: but that it not at all probable, for then we must suppo…
Read the whole note in the consoleJamieson-Fausset-Brown on 2 Kings 9:4
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 (Sa1 16:13); and, in like manner, the commission had, in this instance, been given also a long time before to Elijah [Kg1 19:16], who, for good reasons, left it in charge to Elisha; and he awaited God's time and command for executing it [POOLE].
Adam Clarke on 2 Kings 9:4
The young man the prophet - This should be translated, The servant of the prophet; that is, the servant which Elisha now had in place of Gehazi.
John Gill on 2 Kings 9:4
So the young man, even the young man the prophet, went to Ramothgilead. It is repeated, that it might be observed that it was a young man that went, who was more fit for this service than Elisha, partly because of his age, and partly because he would be less known; as also his age is remarked, this being a bold and daring action in a young man to anoint a new king, as well as it was honourable; and moreover, he was not only one of the sons of the prophets, but was a prophet himself, though young, and still a more fit person for such a service; though the Targum is, a young man, a disciple of the prophets.