Ezekiel 44:11

Yet they shall be ministers in My Sanctuary, in charge of some minor services, having charge at the gates of the house, as porters and guards, and ministering to the house, thereby demoted from the rank and functions of priests to those of ordinary Levites; they shall slay the burnt offering and the sacrifice for the people, and they shall stand before them to minister unto them, no longer in positions of authority and influence, but in the station of porters.