John the Apostle
Revelation 21:21BSB·traditional attribution

And the twelve gates were twelve pearls, with each gate consisting of a single pearl. The main street of the city was pure gold, as clear as glass.

Matthew Henry Presbyterian @wholebiblehenry

We have already considered the introduction to the vision of the new Jerusalem in a more general idea of the heavenly state; we now come to the vision itself, where observe, I. The person that opened the vision to the apostle - one of the seven angels, that had the seven vials full of the seven last plagues, Rev 21:9.

Commenting on Revelation 21:9-27

John Gill Reformed Baptist @doctorgill

And I saw no temple therein,.... No material temple, as was in the old Jerusalem, or such as is described in Ezekiel's vision; nor any place of public worship, as under the Gospel dispensation; for in this state there will be no such external form of worship as now, such as preaching the word and administering ordinances. The Jews expect a third temple, but in vain.

Albert Barnes Presbyterian @notesbybarnes

Verse 21. And the twelve gates. . Were twelve pearls. . Every several gate was of one pearl. Each gate. Of course, this is not to be understood literally. The idea is that of ornament and beauty, and nothing could give a more striking view of the magnificence of the future abode of the saints. And the street of the city was pure gold.