Charles Ellicott Commentary Revelation 21:25-26

"And the gates thereof shall in no wise be shut by day (for there shall be no night there): and they shall bring the glory and the honor of the nations into it:" — Revelation 21:25-26 (ASV)

And the gates of it ...—Better, And the gates (or, gate-towers) will never be shut by day, for night will not be there. The gates will never be shut: all day they will be open, and that day will be for ever, for there will be no night there. All that darkens—the sin that brings night on the soul; the sorrow that brings night on the heart—will be banished for ever. In peace by day, the city gates will be open; nor can there be night when God the Almighty is the Sun. (Ezekiel 38:11.)

Through its open gates they (i.e., men) will bring the glory and honour of the nations into her. As men find that every good gift and every perfect gift is from above, and that their strength is in Christ, without whom they can do nothing, so will their lives bring back to Him the lustre of all their achievements.