Ezekiel 40:17-19

17Then 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.

18And the pavement was by the side of the gates, answerable unto the length of the gates, even the lower pavement.

19Then he measured the breadth from the forefront of the lower gate unto the forefront of the inner court without, an hundred cubits, both on the east and on the north.