Ezekiel 42:3-5

3Opposite the twenty cubits which belonged to the inner courtyard, and opposite the pavement which belonged to the outer courtyard, was gallery (balcony) corresponding to gallery in three stories.

4In front of the [attached] chambers was an inner walkway ten cubits wide and one hundred cubits long; and their entrances were on the north.

5Now the upper chambers were smaller because the galleries took away more space from them than from the chambers on the lower and middle stories of the building;