John Gill, on Neh 7:3

And I said unto them, let not the gates of Jerusalem be opened until the sun be hot,.... Or until the heat of the day, or near noon; at least not till the sun had been up some time, and shone out clearly, and caused much heat; that if any enemies were near, or lying in wait, they might be discovered, and the inhabitants also up and ready to defend themselves: and while they stand by; according to Aben Ezra, Hanani and Hananiah were to be present at the opening and shutting of the gates, and so Grotius; but these being the chief rulers, it is not likely; but rather those whom they appointed to look after them, these were to stand by while their servants did it; they were not to leave it wholly to them, but to see it done themselves: let them shut the doors, and bar them; or "lay hold" (a) on them, handle them to see whether they are shut fast or not: and appoint watches of the inhabitants of Jerusalem, everyone in his watch, and everyone to be over against his house; no foreigners were to be of the watch, only inhabitants, and those everyone in their turn, and to be placed over against where they dwelt; and so it might be thought would be the more careful and diligent in their watch. (a) "et tractate", Junius & Tremellius; "contrectate eas", Piscator.