Whedon's Commentary on the Bible - Revelation 21:12
12. Twelve gates Three, four, and twelve are the predominant numbers; of the last, the twelve tribes are expressly said to be the basis. And the twelve tribes are symbolically the eternal Israel of this eternal city and land. They form the nations of its blessed territory. Twelve angels The porters of the twelve gates, which are, however, ever open. The angel warders, doubtless, see that the citizens of each tribe from the rural regions enter the gate over which its own tribal ... read more
Wesley's Explanatory Notes - Revelation 21:23
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.The glory of God — Infinitely brighter than the shining of the sun. read more