Ezekiel 41:4-6

American Standard Version

⁴ And he measured the length thereof, twenty cubits, and the breadth, twenty cubits, before the temple: and he said unto me, This is the most holy place.

⁵ Then he measured the wall of the house, six cubits; and the breadth of every side-chamber, four cubits, round about the house on every side. ⁶ And the side-chambers were in three stories, one over another, and thirty in order; and they entered into the wall which belonged to the house for the side-chambers round about, that they might have hold therein, and not have hold in the wall of the house.