Matthew Poole and continuators on Ezekiel 40:11

11 And he measured the breadth of the entry of the gate, ten cubits; and the length of the gate, thirteen cubits.

It is meant of the whole length of the entry, or walk through the Porch, which was so wide, and to which they ascended by stairs of a semi-circular form.

The height is meant but 'tis called its length, either because heighth is an erected length. Or rather because thirteen cubits is the greater dimension, and this Interpreters agree in, 'tis the heigth of the gate here measured.