1 Kings 22:30

30. I will disguise myself This rendering, which follows the Septuagint, gives the true sense. The Hebrew is literally, to disguise myself and go into battle, as if the words were an exclamation, and thrown in without proper grammatical connexion. Ahab feared the issue of this battle, for Micaiah’s warning words had been to him an evil omen, and he thought by disguising himself to escape personal injury. Possibly, also, spies had informed him of the order of the king of Syria for his men to fight only with the king of Israel.

Put thou on thy robes Some have imagined that Ahab would have been pleased to have had Jehoshaphat killed in this war that he might seize upon his kingdom and unite it with his own, and therefore counseled him to array himself in his royal robes. As if to favour this thought, the Septuagint has, Put on my apparel. But this is hardly likely, and the sense of the passage more naturally is: Evil is predicted of me, and I will therefore disguise; but this precaution is not necessary for thee, and thou mayest put on thy royal apparel.