Matthew Poole and continuators on Ezekiel 41:11

11 And the doors of the side chambers were toward the place that was left, one door toward the north, and another door toward the South, and the breadth of the place that was left was five cubits round about.

The doors of the lowest row opened into this void paved space.

Beside the particular doors to each chamber, there were two, one on the North, where was a fair Stair-case, which did lead up to every story, and above these to the top of the Temple. And so another like this on the South, excepting that this South Stair-case lead not up to the top of all, as that North Stair-case did.