3. Perpetuity. This crowns all the rest (v. 20): Judah shall dwell for ever (when Egypt and Edom are made a desolation), and Jerusalem shall continue from generation to generation. This is a promise, and a precious promise it is, (1.) That the church of Christ shall continue in the world to the end of time. As one generation of professing Christians passes away, another shall come, in whom the throne of Christ shall endure for ever, and the gates of hell shall not prevail against it. (2.) That all the living members of that church (Judah and Jerusalem are put for the inhabitants of that city and country, Matt. iii. 5) shall be established in their happiness to the utmost ages of eternity. This new Jerusalem shall be from generation to generation, for it is a city that has foundations, not made with hands, but eternal in the heavens.