Commentary on the Apocalypse
Chapter 19: From the Twenty-First and Twenty-Second Chapters
And the city is built as a square. The city that he says is square is also shining with gold and precious stones. It has a holy street, a river running through the middle of it, and the tree of life on both sides, bearing twelve kinds of fruit through the twelve months. The sun does not give light there, because the Lamb is its light. Its gates are each made of a single pearl. There are three gates on each of the four sides, and they cannot be shut. I say that, by the square city, he shows the united multitude of the saints, in whom the faith could in no way waver. Noah was commanded to make the ark out of squared beams, so that it could withstand the force of the flood. In the same way, by the precious stones, he points to holy men who cannot waver under persecution. They could not be moved by the storm of persecutors, nor be broken away from the true faith by the force of the rain, because they are joined together with pure gold. With such people the city of the great King is adorned. Also, the streets represent their hearts, purified from all uncleanness and transparent with glowing light, so that the Lord may rightly walk back and forth in them. The river of life shows that the grace of spiritual teaching flowed through the minds of the faithful, and that many flowering kinds of fragrance grew in it. The tree of life on either bank points to the coming of Christ in the flesh. He satisfied the peoples wasted by famine, who received life from the One through the wood of the Cross, with the announcement of God’s word. And when he says that the sun is not needed in the city, he clearly shows that the Creator shines in the middle of it as the spotless light. No mind has been able to understand his brightness, and no tongue has been able to describe it.
When he says that there are three gates on each of the four sides, each made of a single pearl, I think these are the four virtues: prudence, fortitude, justice, and temperance. These virtues are joined with one another. And when they are brought together, they make the number twelve. We believe the twelve gates are the number of the apostles. They shine in the four virtues like precious stones. They show the light of their teaching among the saints, and make it enter the heavenly city, so that through fellowship with them the choir of angels may rejoice. And since the gates cannot be shut, it is clearly shown that no storm of opposition can separate the teaching of the apostles from what is right. Even if the floods of the nations and the empty superstitions of heretics should rise up against their true faith, they are overcome and will be dissolved like foam. For Christ is the Rock through whom, and on whom, the Church is founded. Therefore it is not overcome by any marks left by raging men. So we must not listen to those who assure themselves that there will be an earthly reign of a thousand years, that is, those who think like the heretic Cerinthus. For the kingdom of Christ is already eternal in the saints, although the glory of the saints will be revealed after the resurrection.