Commentary for Ezekiel 40:12

And a border [area] was before the cells of one cubit, etc. The cells on either side of the gate were inset [away] from being in line with the area of the inward-going hall, a cubit to the north and a cubit to the south. For he already made it clear that on the inside, it [the space] was extended beyond from the [the area] facing the space of the gate, a cubit and a half to the north and likewise to the south. Now he explains that the cells which were on the outside were recessed to the north, one cubit more than the hall, and likewise one cubit to the south. As a result, they were recessed from the area of the [gate’s] entrance’s width, two and a half cubits to this side and two and a half cubits to this side. This is [the meaning of] the word וּגְבוּל, somayl in Old French, border, limit, an empty place. The wall of the cell was five cubits thick, resulting in the thickness of the northern wall of the northern cell, a nd the thickness of the northern wall of the hall, ending opposite each other. For the wall of the hall was six cubits thick and the wall of the cell was five, and it was extended one cubit inward opposite the thickness of the wall of the hall, and likewise, to the south.