Ezekiel 42:3-5

3Opposite the twenty cubits which were for the inner court, and opposite the pavement which was for the outer court, was gallery against gallery in three stories .

4And before the chambers was a walk of ten cubits breadth inward, a way of one cubit; and their doors toward the north.

5Now the upper chambers were narrower: for the galleries were higher than these, than the lower, and than the middle ones of the building.12