The interpretation timeline
Revelation 21:2 Douay-Rheims

And I John saw the holy city, the new Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband.

A.D. 202 – 1871 8 witnesses

Patristic

before A.D. 750
202
A.D.
Irenaeus Patristic
c. A.D. 130–202
“But in the times of the kingdom, the earth has been called again by Christ [to its pristine condition], and Jerusalem rebuilt after the pattern of the Jerusalem above, of which the prophet Isaiah says, "Behold, I have depicted thy walls upon my hands, and thou art always in my sight," And the apostle, too, writing to the Galatians, says in like manner, "But the Jerusalem which is above is free, which is the mother of us all." He does not say this with any thought of an erratic Aeon, or of any other power which departed from the Pleroma, or of Prunicus, but of the Jerusalem which has been delineated on [God's] hands. And in the Apocalypse John saw this new [Jerusalem] descending upon the new earth. When these things, therefore, pass away above the earth, John, the Lord's disciple, says that the new Jerusalem above shall [then] descend, as a bride adorned for her husband; and that this is the tabernacle of God, in which God will dwell with men. Of this Jerusalem the former one is an image-that Jerusalem of the former earth in which the righteous are disciplined beforehand for incorruption and prepared for salvation. And of this tabernacle Moses received the pattern in the mount; and nothing is capable of being allegorized, but all things are stedfast, and true, and substantial, having been made by God for righteous men's enjoyment. For as it is God truly who raises up man, so also does man truly rise from the dead, and not allegorically, as I have shown repeatedly. And as he rises actually, so also shall he be actually disciplined beforehand for incorruption, and shall go forwards and flourish in the times of the kingdom, in order that he may be capable of receiving the glory of the Father. Then, when all things are made new, he shall truly dwell in the city of God. For it is said, "He that sitteth on the throne said, Behold, I make all things new. And the Lord says, Write all this; for these words are faithful and true. And He said to me, They are done." And this is the truth of the matter.”
Source
220
A.D.
Tertullian Patristic
c. A.D. 150–220
“But we do confess that a kingdom is promised to us upon the earth, although before heaven, only in another state of existence; inasmuch as it will be after the resurrection for a thousand years in the divinely-built city of Jerusalem, "let down from heaven," which the apostle also calls "our mother from above; " and, while declaring that our poli/teuma, or citizenship, is in heaven, he predicates of it that it is really a city in heaven.”
Source
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“This city is said to come down out of heaven in the sense that God created it by means of heavenly grace, as he told it through Isaiah: "I am the Lord creating thee." Indeed, its descent from heaven began with the beginning of time, since it is by God's grace coming down from above through the "laver of regeneration" in the Holy Spirit sent from heaven that its citizenship has continuously grown up on earth. Yet only after God's last judgment, the one he has deputed to Jesus Christ his Son, will his tremendous gift of grace be revealed so brightly in [Jerusalem] that in this new brightness there will remain no traces of its earthly blemishes. For then its members' bodies will pass over from mortal corruptibility to the new immortality of incorruption.”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And I John saw the holy city,.... The same with the beloved city in Rev 20:9 the church of God: sometimes the church militant is called a city, of which the saints are now fellow citizens, governed by wholesome laws, and enjoying many privileges; but here the general assembly and church of the firstborn, or all the elect of God, are intended, the whole body and society of them, being as a city, compact together; called holy, not only because set apart to holiness by God the Father, and their sins expiated by the blood of Christ, or because he is made sanctification to them, or because internally sanctified by the Spirit of God, which now is but in part; but because they will be perfectly holy in themselves, without the being of sin in them, or any spot of it on them: and John, for the more strong ascertaining the truth of this vision, expresses his name, who saw it, to whom God sent his angel, and signified to him by these Apocalyptic visions what should be hereafter; though the name is left out in the Alexandrian copy, and in the Syriac, Arabic, and Ethiopic versions: new Jerusalem; the church of God, both in the Old and New Testament, is often called Jerusalem, to which its name, which signifies the vision of peace, agrees; it was the city of the great King, whither the tribes went up to worship; it was a free city, and a fortified one: the Gospel church state in its imperfection is called the heavenly Jerusalem, and the Jerusalem above, which is free, and the mother of all; and here the church in its perfect state is called the new Jerusalem, where will be complete peace and prosperity; and which is called new, because it has its seat in the new heaven and new earth: the inhabitants of which will appear in their new and shining robes of immortality and glory; and to distinguish it from the old Jerusalem, and even from the former state of the church; for this will be "the third time" that Jerusalem will be built, as say the Jews, namely, in the time of the King Messiah (r): coming down from God out of heaven; which designs not the spiritual and heavenly original of the saints, being born from above, on which account the church is called the heavenly Jerusalem; but a local descent of all the saints with Christ from the third heaven into the air, where they will be met by living saints; and their bodies being raised and united to their souls, they will reign with Christ in the new earth: and this is "the building which the Jews say God will prepare for the Jerusalem which is above, "to descend into" (s):'' prepared as a bride adorned for her husband; Christ is the husband, or bridegroom, and the church is his spouse, and bride; and in these characters they will both appear at this time, when the marriage between them will be consummated: and the church may be said to be prepared as such, when all the elect of God are gathered in, the number of the saints is perfected; when the good work of grace is finished in them all, and they are all arrayed in the righteousness of Christ: and to be "adorned", when not only they are clothed with the robe of righteousness, and garments of salvation, and are beautified with the graces of the Spirit, but also with the bright robes of immortality and glory. The phrase is Jewish, and is to be read exactly as here in the book of Zohar (t). (r) Zohar in Gen. fol. 126. 4. (s) Ib. fol. 103. 4. (t) Zohar in Gen. fol. 53. 2.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“And I John - The writer of this book; whether the evangelist and apostle, or John the Ephesian presbyter, has been long doubted in the Church. New Jerusalem - See the notes on Gal 4:24-27 (note). This doubtless means the Christian Church in a state of great prosperity and purity; but some think eternal blessedness is intended. Coming down from God - It is a maxim of the ancient Jews that both the tabernacle, and the temple, and Jerusalem itself, came down from heaven. And in Midrash Hanaalem, Sohar Gen. fol. 69, col. 271, Rab. Jeremias said, "The holy blessed God shall renew the world, and build Jerusalem, and shall cause it to descend from heaven." Their opinion is, that there is a spiritual temple, a spiritual tabernacle, and a spiritual Jerusalem; and that none of these can be destroyed, because they subsist in their spiritual representatives. See Schoettgen.”
Source
1849
A.D.
1774–1849
“Coming down from God out of heaven. By the city we must understand its citizens, the Angels and saints. (Witham) — Justice, innocence, the good works of the saints, are the ornaments of the inhabitants of this new Jerusalem, the Church triumphant. If the world of the old Adam has appeared so beautiful, so magnificent, good God, what will be the riches of that which is made for Jesus Christ, the second Adam, and for his members! O Jesus! Father of the world to come, render us worthy of this new and everlasting world, and give us a disgust, a mortal hatred, for that which perishes, and which is the cause of our perdition.”
Source
1871
A.D.
1871
“And I John--"John" is omitted in A, B, Vulgate, Syriac, Coptic, and ANDREAS; also the "I" in the Greek of these authorities is not emphatic. The insertion of "I John" in the Greek would somewhat interfere with the close connection which subsists between "the new heaven and earth," Rev 21:1, and the "new Jerusalem" in this verse. Jerusalem . . . out of heaven-- (Rev 3:12; Gal 4:26, "Jerusalem which is above"; Heb 11:10; Heb 12:22; Heb 13:14). The descent of the new Jerusalem out of heaven is plainly distinct from the earthly Jerusalem in which Israel in the flesh shall dwell during the millennium, and follows on the creation of the new heaven and earth. John in his Gospel always writes [Greek] Hierosoluma of the old city; in the Apocalypse always Hierousaleem of the heavenly city (Rev 3:12). Hierousaleem is a Hebrew name, the original and holy appellation. Hierosoluma is the common Greek term, used in a political sense. Paul observes the same distinction when refuting Judaism (Gal 4:26; compare Gal 1:17-18; Gal 2:1; Heb 12:22), though not so in the Epistles to Romans and Corinthians [BENGEL]. bride--made up of the blessed citizens of "the holy city." There is no longer merely a Paradise as in Eden (though there is that also, Rev 2:7), no longer a mere garden, but now the city of God on earth, costlier, statelier, and more glorious, but at the same time the result of labor and pains such as had not to be expended by man in dressing the primitive garden of Eden. "The lively stones" were severally in time laboriously chiselled into shape, after the pattern of "the Chief corner-stone," to prepare them for the place which they shall everlastingly fill in the heavenly Jerusalem.”
Source

Undated

date unknown
date
unknown
Glossa Ordinaria Medieval
“As a bride adorned. As a bridegroom sends gifts ahead to the bride before he weds her, so Christ sends ahead to the Church faith and virtues and good works before he receives her into glory.”
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.