Albert Barnes' Notes on the Whole Bible - Revelation 21:23
And the city had no need of the sun, neither of the moon, to shine in it - This imagery seems to be derived from Isaiah 9:19-20. See notes on those verses. No language could give a more striking or beautiful representation of the heavenly state than what is here employed.For the glory of God did lighten it - By the visible splendor of his glory. See the notes on Revelation 21:11. That supplied the place of the sun and the moon.And the Lamb is the light thereof - The Son of God; the Messiah. See... read more
The Pulpit Commentary - Revelation 21:24
And the nations of them which are saved shall walk in the light of it; and the nations shall walk by means of her light. Omit "of them which are saved." The description, following that of Isaiah, makes use of earthly symbolism; but it is not, therefore, to be supposed (as Afford) that there will be hereafter a real earth with inhabitants. "The nations" are the redeemed, described in this way on account of their selection from every "kindred, and nation, and tribe, and tongue" ( Revelation... read more