Nehemiah 7:3-4

3I said to them, “Do not leave the gates open during the hottest part of the day. And even while the gatekeepers are on duty, have them shut and bar the doors. Appoint the residents of Jerusalem to act as guards, everyone on a regular watch. Some will serve at sentry posts and some in front of their own homes.”

4At that time the city was large and spacious, but the population was small, and none of the houses had been rebuilt.