Luria quotes a story where Hai ben Sherira, Hai Gaon practiced a minhag to travel to Jerusalem for Sukkot and circle the Temple Mount with hundreds of kohanim with the company of Elijah the Prophet. One year a student of his noticed rav Hai laughing during the procession, at the completion of the procession he queried his rabbi as to why, to which rav Hai responded that Elijah revealed to him that, from among the hundreds of kohanim that accompanied him in a haughty way, none were legitimate kohanim aside for one kohen who proceeded humbly.