Ezekiel 40:45

And without the inner gate were the chambers of the singers in the inner court, which was at the side of the north gate; and their prospect was toward the south: one at the side of the east gate having the prospect toward the north.

And the chamber whose prospect is toward the north is for the priests, the keepers of the charge of the altar: these are the sons of Zadok among the sons of Levi, which come near to the LORD to minister unto him.