Ezekiel 40:44-46

From the outside to the inner gate were chambers for the singers in the inner courtyard, one of which was beside the north gate, with its front toward the south, and one beside the south gate facing toward the north. He [who was guiding me] said to me, “This is the chamber which faces toward the south; it is for the priests who have the responsibility and take care of the temple; but the chamber which faces toward the north is for the priests who have the responsibility and take care of the altar. These are the sons of Zadok, who [alone] from the sons of Levi come near to the LORD to minister to Him.”