The sun and the moon are the two great luminaries of the world, which God hath made, the one to rule the day, the other to rule the night; in heaven there will be no need of any of these. Light, in Scripture, (in its metaphorical notion), signifies knowledge or comfort; there will in heaven be no need of any created beings, to help us to either of these; God and Christ shall there fill the souls of his saints with knowledge and joy not to be expressed.
Related Commentaries of Revelation 21:23
Revelation 21:23
23 And the city had no need of the sun, neither of the moon, to shine in it: for the glory of God did lighten it, and the Lamb is the light thereof.