1 Kings 22:29 - Joseph Benson’s Commentary on the Old and New Testaments

So the king of Israel and Jehoshaphat went up, &c. Notwithstanding the declaration Micaiah had made of God's decree, Jehoshaphat was persuaded by Ahab and other prophets to go on this expedition; partly because Micaiah was a person unknown to him, and both he and the other prophets professing to speak from God, it seemed difficult to him to determine the controversy between them, which, he probably thought, only the event could decide: and partly because the war was just and lawful, being undertaken to recover Ahab's rights, which the Syrian king unjustly detained from him.