Nehemiah 7:3

And I said unto them, Let not the gates of Jerusalem be opened until the sun be hot, the custom being to open them at sunrise, when the enemies might still take advantage of the shadows to attempt an attack; and while they stand by, that is, the members of the guard, ready to defend the gates, let them shut the doors and bar them, this being done at sunset; and appoint watches of the inhabitants of Jerusalem, men living throughout the city, every one in his watch, and every one to be over against his house, mounting guard, as sentinel, near his own property, in order to prevent any gathering of people that may have entered into the city for the purpose of starting a riot.