Both the king of Israel and the king of Judah were originally present at the siege of Ramoth-gilead (ch. 8:28). When Joram was wounded he took his departure for his country residence at Jezreel, and was soon followed by Ahaziah. If both kings left before the siege ended, this would have had a discouraging effect on the army, and would probably be interpreted as indifference or cowardice. If, while Jehu and the army were undergoing the hardships and dangers of battle, the kings were taking their ease at the summer palace, this would explain the immediate and unrestrained enthusiasm with which Jehu was hailed as king.
Joram lay.
Joram had not yet recovered from his wounds and was still confined to his bed at Jezreel. But the sequel shows that he could not have been too seriously ill, for he was well enough to enter his chariot and go out to meet Jehu (v. 21).
Rode in a chariot.
No time was to be lost. Jehu made every effort to get to Jezreel before anyone had had the opportunity of telling the king what had just taken place at Ramoth-gilead. He rode in a chariot, accompanied by a small group of men, but the army was left on guard in Gilead against any surprise attack by the Syrians.