John Wesley on Ezekiel 40:18

The pavement - That mentioned, ver.17. By the side - That part which lay on each side of the gate, and from thence spread itself toward the chambers, leaving a space of pavement of equal breadth with the porch, or gate in the middle. The length - The length was measured fifty cubits. The inner pavement - The side pavement was laid somewhat lower than this middle pavement, not only for state, but for the more convenient, keeping it clean; so the middle pavement rose with a little convex surface.