The interpretation timeline
Revelation 21:10 Douay-Rheims

And he took me up in spirit to a great and high mountain: and he shewed me the holy city Jerusalem coming down out of heaven from God,

A.D. 220 – 1871 6 witnesses

Patristic

before A.D. 750
220
A.D.
Tertullian Patristic
c. A.D. 150–220
“This both Ezekiel had knowledge of and the Apostle John beheld. And the word of the new prophecy which is a part of our belief, attests how it foretold that there would be for a sign a picture of this very city exhibited.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And he carried me away in the Spirit,.... John was in an ecstasy, as in Rev 1:10 and in the thoughts and apprehensions of his mind and spirit, it seemed to him as if he was carried away from one place to another; for this was not a corporeal sight, nor were any of the visions he had, but what was represented to his mind or spirit; it being with him as it was with the Apostle Paul when he was caught up to the third heaven, who knew not whether he was in the body or out of the body. The Ethiopic version renders it, "the Spirit brought me"; not the evil spirit Satan, who took up our Lord corporeally, and carried him to an exceeding high mountain, and showed him all the kingdoms of this world, and their glory, Mat 4:8 but either a good angel, or the Spirit of God: to a great and high mountain; to such an one was Ezekiel brought in the visions of God, when the frame of a city and temple was shown him, with their dimensions, Eze 40:2 as here a city is shown to John, with its wall, gates, foundations, and their measures: and he was brought to such a place, partly that he might have the more plain and full view of it; and partly to suggest unto him, that now the church of Christ was established upon the top of the mountains, and exalted above the hills, and was a city on a hill, which could not be hid, Isa 2:2. And showed me that great city; which is no other than the church, the bride, the Lamb's wife; just as the apostate church, all along in this book before, is called the great city, Rev 11:8 but now that being demolished, there is no other great city in being but the church of Christ, called a city before; Rev 21:2 here a "great one", not only because of its prodigious large dimensions, Rev 21:16 but because of the number of its inhabitants, being such as no man can number; and because it is the residence of the great King, the tabernacle of God will be in it; though this epithet is left out in the Alexandrian copy, and in the Vulgate Latin and all the Oriental versions: "the holy Jerusalem"; called "the new Jerusalem", Rev 21:2 here "holy", in allusion to the city of Jerusalem, which was called the holy city, Mat 4:5 on account of the temple in it, the place of divine worship; but here this city is so called, because it is the residence of the holy God, Father, Son, and Spirit, inhabited only by holy men, made perfectly so, and encompassed by holy angels. Descending out of heaven from God; See Gill on Rev 21:2.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“To a great and high mountain - That, being above this city, he might see every street and lane of it. The holy Jerusalem - See on Rev 21:2 (note).”
1863
A.D.
1796–1863
“G. P. " that great city, the holy Jerusalem." The epithet "great" is want- ing in the above manuscripts, and in the Syriac and Arabic versions.”
1871
A.D.
1871
“The words correspond to Rev 17:3, to heighten the contrast of the bride and harlot. mountain--Compare Eze 40:2, where a similar vision is given from a high mountain. that great--omitted in A, B, Vulgate, Syriac, Coptic, and CYPRIAN. Translate then, "the holy city Jerusalem." descending--Even in the millennium the earth will not be a suitable abode for transfigured saints, who therefore shall then reign in heaven over the earth. But after the renewal of the earth at the close of the millennium and judgment, they shall descend from heaven to dwell on an earth assimilated to heaven itself. "From God" implies that "we (the city) are God's workmanship."”
Source

Undated

date unknown
date
unknown
Glossa Ordinaria Medieval
“Into a great mountain. Christ is the mountain, because he is the fortification of his own; great, because he fills the whole world; high, because unconquerable. He showed me the city. And upon that mountain he showed the foundation of the Church.”
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.