16 Let us also with one voice say what follows: “Blessed be the Lord out of Zion, who dwells in Jerusalem”. Out of Zion is Jerusalem too. Zion is “watching,” Jerusalem the “vision of peace.” In what Jerusalem will He dwell now? In that which has fallen? Nay, but in that which is our mother, which is in the heavens, of which it is said, “The desolate has more children than she which has a husband.” For now the Lord is from Zion, because we watch when He will come; now as long as we live in hope, we are in Zion. When our way is ended, we shall dwell in that city which will never fall, because the Lord dwells in her, and keeps her, which is the vision of peace, the eternal Jerusalem; for the praise of which, my brethren, language suffices not; where we shall find no enemy, either within the Church or without the Church, neither in our flesh, nor in our thoughts. For “death shall be swallowed up in victory,” and we shall be free to see God in eternal peace, being made citizens of Jerusalem, the city of God.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)