Ezekiel 40:44-46

44Outside the inner gate, within the inner court, were two chambers,1 one beside the north gate and facing south, and another beside the south gate2 and facing north.

45Then the man said to me: “The chamber that faces south is for the priests who keep charge of the temple, 46and the chamber that faces north is for the priests who keep charge of the altar. These are the sons of Zadok, the only Levites who may approach the LORD to minister before Him.”