Charles Ellicott Commentary Nehemiah 3:13

"The valley gate repaired Hanun, and the inhabitants of Zanoah; they built it, and set up the doors thereof, the bolts thereof, and the bars thereof, and a thousand cubits of the wall unto the dung gate." — Nehemiah 3:13 (ASV)

A thousand cubits. —Not so much “built” as “strengthened.” This comparatively large space—mentioned in round numbers—had probably suffered less damage, and therefore needed less repairing.