Because Hazael certainly would do his best to retake the city at his earliest opportunity. Israel would therefore have to continue to stand guard against Hazael if Ramoth-gilead was to be retained under Israelite control.

This is an important statement, because it shows definitely that the siege had been successful and that the city had come into Israelite hands. “Joram” should probably here be taken to stand not so much for the man as for the nation he ruled. If Joram left during the siege, Jehu had probably by now taken the city in the name of the king and was standing guard with the army of Israel, to prevent the Syrians from recapturing it.

The former king was still alive and supposedly still ruling upon his throne. So the actions in which Jehu was taking a part were in reality conspiracy against Joram and the house of Omri and Ahab.