Jamieson, Fausset and Brown on 1 Kings 22:24-25

24-25. Zedekiah the son of Chenaanah went near, and smote Micaiah on the cheek--The insolence of this man, the leader of the false prophets, seems to have been provoked by jealousy at Micaiah's assumed monopoly of the spirit of inspiration. This mode of smiting, usually with a shoe, is both severe and ignominious. The calm reply of the Lord's prophet consisted in announcing the fate of the false prophets who suffered as the advisers of the disastrous expedition.