Albert Barnes Commentary Ezekiel 40:17-19

"Then brought he me into the outer court; and, lo, there were chambers and a pavement, made for the court round about: thirty chambers were upon the pavement. And the pavement was by the side of the gates, answerable unto the length of the gates, even the lower pavement. Then he measured the breadth from the forefront of the lower gate unto the forefront of the inner court without, a hundred cubits, [both] on the east and on the north." — Ezekiel 40:17-19 (ASV)

The “outward” or outer “court” (o, Plan II) corresponds to what was in Herod’s temple the Court of Women, into which all Jews, but not Gentiles, were admitted (Ezekiel 40:17).

Chambers - (I) See (Jeremiah 35:2).

A pavement - (H) This was of mosaic work (2 Chronicles 7:3; Esther 1:6), which formed a border of forty-four cubits. It was on each side of the court in which there were gates, that is, on east, north, and south. It was called the “lower pavement” to distinguish it from the pavement of the inner court, because the outer court was lower than the inner (Ezekiel 40:31). (Ezekiel 40:19)

There were eastern, northern, and southern gates of entrance from the outer to the inner court (B).

Without - This means not as in the margin, but looking outward; that is, the outward front of the inner gate toward the outer court.