Ezekiel 40:17-19

17Then he brought me into the outer court; and there were chambers and a pavement made all around the court; thirty chambers faced the pavement.

18The pavement was by the side of the gateways, corresponding to the length of the gateways; this was the lower pavement.

19Then he measured the width from the front of the lower gateway to the front of the inner court exterior, one hundred cubits toward the east and the north.