Ezekiel 42:1, 3, 7-9, 14

Then he brought me forth into the utter court, the way toward the north: and he brought me into the chamber that was over against the separate place, and which was before the building toward the north.

Over against the twenty cubits which were for the inner court, and over against the pavement which was for the utter court, was gallery against gallery in three stories.

And the wall that was without over against the chambers, toward the utter court on the forepart of the chambers, the length thereof was fifty cubits. For the length of the chambers that were in the utter court was fifty cubits: and, lo, before the temple were an hundred cubits. And from under these chambers was the entry on the east side, as one goeth into them from the utter court.

When the priests enter therein, then shall they not go out of the holy place into the utter court, but there they shall lay their garments wherein they minister; for they are holy; and shall put on other garments, and shall approach to those things which are for the people.