Revelation 21:12; A Wall Great and High

Revelation 21:12 (KJV)  And had a wall great and high, and had twelve gates, and at the gates twelve angels, and names written thereon, which are the names of the twelve tribes of the children of Israel: 

The city wall with her twelve gates is the next item to catch the prophet’s attention – And had a wall great and high, and had twelve gates, and at the gates twelve angels, and names written thereon, which are the names of the twelve tribes of the children of Israel: 

The wall around the city is sizeable, making it one of the more conspicuous features of the city. The purpose of the wall is not to help defend the city, because there is no enemy to defend against. It rather is a constant reminder of the eternal security of the city’s inhabitants (Kiddle). Such a wall was a conventional feature of ancient cities (cf. Isaiah 26:1; Zechariah 2:5) (Swete). Verse 18 will reveal that the wall is jasper as is her first foundation. (v19), making it resemble the glory of God.

Isaiah 26:1 (KJV)  In that day shall this song be sung in the land of Judah; We have a strong city; salvation will Godappoint for walls and bulwarks. 

Zechariah 2:5 (KJV)  For I, saith the LORD, will be unto her a wall of fire round about, and will be the glory in the midst of her. 

Revelation 21:18-19 (KJV) And the building of the wall of it was of jasper: and the city was pure gold, like unto clear glass. And the foundations of the wall of the city were garnished with all manner of precious stones. The first foundation was jasper; the second, sapphire; the third, a chalcedony; the fourth, an emerald;

[Robert L. Thomas, Revelation 8-22 – An Exegetical Commentary, Moody, 462]