Ezekiel Chapter 42 Vs. 6

 The Temple's Chambers

For they were in three stories, but had not pillars as the pillars of the courts: therefore the building was straitened more than the lowest and the middlemost from the ground. Eze 42:6

chambers were shorter... The third stories or top chambers were shorter than the first and second story rooms (Eze. 42:5-8).

We see the reason for them being set in for strength. There were no supporting pillars and they had to draw their strength from the wall.

These rooms were three stories high, with the rooms on the third level being narrower than those on the first and second floors (Eze. 42:3-6).