Ezekiel 40:17-19

17Then he brought me into the outer court. There I saw some rooms and a pavement that had been constructed all around the court; there were thirty rooms along the pavement.

18It abutted the sides of the gateways and was as wide as they were long; this was the lower pavement.

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