What does Nehemiah 7:3 mean?

I told them, 'Don’t open the gates of Jerusalem until the sun is high. And while the guards are still on duty, shut and lock the doors. Also, appoint people from Jerusalem as guards, some at their posts and some near their own homes.' Nehemiah 7:3 - Modern Text Bible

(Nehemiah gave strict instructions for guarding the city, making sure the gates were only open when it was safe and that residents took responsibility for their own neighborhoods.)