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: (Revelation 21:12)
The New Jerusalem is pictured as having angelic gatekeepers.
Twelve gates.
Compare the city described by Ezekiel (ch. 48:31-34).
Wall great and high.
Such walls were built around ancient cities for protection against enemies. John’s imagery is borrowed in part from the description of the city Ezekiel saw (see on Eze. 48:35). The picture is that of an ancient city with walls and gates. These were terms with which the apostle was familiar, and Inspiration chose to reveal the glories of the eternal city to him in terms that he understood. Human language and human portrayals cannot adequately represent the grandeur of that celestial city. In pictorial prophecy the degree of identity between the picture and the actual calls for careful interpretation (see on Eze. 1:10; 40:1).
Twelve tribes.
See Eze. 48:31-34. For the picture of spiritual Israel reckoned by tribes see on Rev. 7:4.