Jamieson, Fausset and Brown on Nehemiah 7:4

4. Now the city was large and great--The walls being evidently built on the old foundations, the city covered a large extent of surface, as all Oriental towns do, the houses standing apart with gardens and orchards intervening. This extent, in the then state of Jerusalem, was the more observable as the population was comparatively small, and the habitations of the most rude and simple construction--mere wooden sheds or coverings of loose, unmortared stones.