Shorter — At first view it should seem to refer to the length, but indeed it refers to the height of the chambers, of which the lowest chamber was highest, the second lower pitched than the first, yet of greater height than the uppermost between the floor and ceiling.
Related Commentaries of Ezekiel 42:5
Ezekiel 42:5
5 Now the upper chambers were shorter: for the galleries were highera than these, than the lower, and than the middlemost of the building.