He was of the prophets - Josephus and others conjecture that this prophet was Micaiah, the son of Imlah (but compare 1 Kings 20:13 note).
Related Commentaries of 1 Kings 20:41
1 Kings 20:41
41 And he hasted, and took the ashes away from his face; and the king of Israel discerned him that he was of the prophets.