New Defender's Study Bible Notes
21:21 twelve pearls. The pearly gates, each consisting of 1380 miles of solid pearl, are never closed (Revelation 21:25), thus providing access to the city at every level throughout its great height.
21:21 street of the city. The “street of the city” must be an inter-connected complex of both horizontal streets and vertical streets (like elevator shafts), all of translucent gold. The glorified bodies of the saints will be like that of Christ (Philippians 3:21), capable of moving at great speed through space (note John 20:17; also Daniel 9:21-23), and therefore can easily move both horizontally and vertically about the city. How it is that the streets of pure gold can also be like transparent glass we do not yet understand. However, “the gold is mine, saith the LORD” (Haggai 2:8), and He can do with it as He will. The city will be of indescribable beauty in its total aspect (I Corinthians 2:9).