Revelation 21:21 Commentary - The Cambridge Bible for Schools and Colleges
21. pearls ] Contrast Isa 54:12, where they are carbuncles.
the street ] Or “square:” see on Rev 11:8. The City has one great space in the midst of it, like an Agora or Forum: but the word Agora would have associations, commercial or political, that would be incongruous with the repose of this city. It is probably the pavement of the street which, like the walls of the houses, is of transparent gold.
Consult other comments:
The Cambridge Bible for Schools and Colleges
The Cambridge Bible for Schools and Colleges is a biblical commentary set published in parts by Cambridge University Press from 1882 onwards. Anglican bishop John Perowne was the general editor. The first section published was written by theologian Thomas Kelly Cheyne and covered the Book of Micah.
Perowne exercised limited editorial control over the writers of individual commentaries: his aim was "to leave each contributor to the unfettered exercise of his own judgment".