Ezekiel 42:3-7

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

Now the upper chambers were shorter: for the galleries were higher than these, than the lower, and than the middlemost of the building.

For they were in three stories, but had not pillars as the pillars of the courts: therefore the building was straitened more than the lowest and the middlemost from the ground.

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.