Ezekiel 41:5-7

5Then he measured the wall of the temple, six cubits [thick, to accommodate side chambers]; and the width of every side chamber, four cubits, all around the temple on every side.

6The side chambers were three stories [high], one above another, and thirty chambers in each story; and the side chambers extended to the wall which stood on their inward side all around, so that they would be attached, but not attached to the wall of the temple itself.

7The side chambers became wider at each successive level as they encompassed the temple. Because the structure surrounding the temple went higher by stages on all sides of the temple, for that reason the width of the temple increased as it went higher; and thus one went up from the lowest story to the highest one by way of the second story.