Ezekiel 40:17-19

17Then he brought me into the outer court, and there were chambers and a pavement laid out all around the court. Thirty chambers faced the pavement, 18which flanked the gateways and corresponded to the length of the gates; this was the lower pavement.

19Then he measured the distance from the front of the lower gateway to the outside of the inner court; it was a hundred cubits1 on the east side as well as on the north.