Charles Ellicott Commentary 2 Chronicles 18:29

"And the king of Israel said unto Jehoshaphat, I will disguise myself, and go into the battle; but put thou on thy robes. So the king of Israel disguised himself; and they went into the battle." — 2 Chronicles 18:29 (ASV)

I will disguise myself, and will go. —Literally, disguising myself and entering! A hurried exclamatory mode of speaking.

They went. —Kings, he (Ahab) went into the battle. So some Hebrew manuscripts, Septuagint, Syriac, Vulgate, Arabic, and Targum.