Ezekiel 40:46 (KJV)

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 he said unto me, This chamber, whose prospect is toward the south, is for the priests, the keepers of the charge of the house.

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.

So he measured the court, an hundred cubits long, and an hundred cubits broad, foursquare; and the altar that was before the house.

And he brought me to the porch of the house, and measured each post of the porch, five cubits on this side, and five cubits on that side: and the breadth of the gate was three cubits on this side, and three cubits on that side.