Revelation 21:25 - Matthew Poole's English Annotations on the Holy Bible

And the gates of it shall not be shut at all by day: the reason of shutting a city's gates, is either to shut out enemies, or to keep in such as are within: there will be no need of shutting these gates on either of these accounts; there will be no enemies to fear, and those that are within this city will have no need nor desire to go out. For there shall be no night there: we do not ordinarily shut our city gates by day, but there shall be nothing but day, no night in a natural or metaphorical sense.