There stood a watchman on the tower— In times of peace as well as war, it was usual to have watchmen set on high and eminent places wherever the king was, to prevent his being surprised. Thus David at Jerusalem was informed by the watchmen, that his sons were escaped from the slaughter of Absalom, when he thought them all lost, 2 Samuel 13:34.; and therefore Jehoram, who had an armor lying before Ramoth-gilead, had good reason to keep a watchful eye upon every motion, especially from that quarter. See Calmet.
Related Commentaries of 2 Kings 9:17
2 Kings 9:17
17 And there stood a watchman on the tower in Jezreel, and he spied the company of Jehu as he came, and said, I see a company. And Joram said, Take an horseman, and send to meet them, and let him say, Is it peace?