For thus saith Isaiah about this period of a thousand years: For the heaven shall be new and the earth new, and they shall not remember the former things, nor shall they come into their heart, but joy and gladness shall they find in her, such as I create. For, behold, I make Jerusalem gladness and My people joy, and I will be glad over Jerusalem, and will rejoice over My people. And there shall no more be heard in her sound of weeping nor sound of crying, and there shall not be there one of untimely days any more, and an aged man who does not fill out his time. For the youth shall be a hundred years old, and the sinner that dieth shall be a hundred, years old and (still) accursed.
And they shall build houses and live in them themselves, and shall plant vineyards, and themselves eat their produce. They shall not build and others inhabit, and shall not plant and others eat; for according to the days of the tree of life shall be the days of My people; the works of their toil shall grow old. My elect shall not toil in vain, nor bring forth children for a curse; for they shall be a righteous seed blessed by the Lord, and their offering with them. And it shall be that before they have cried, I will hear them; while they are still speaking, I will say: What is it? Then wolves and lambs shall feed together, and a lion shall eat stubble like an ox, but a serpent earth as it were bread. They shall not hurt nor ruin on the holy mountain, saith the Lord.Isaiah 65:17-25
Now we are of opinion, I said, that by these words, For according to the days of the tree shall be the days of my people, the works of their toil shall grow old, he signifies a thousand years in a mystery. For as it was said to Adam that in the day in which he should eat of the tree, in that he should die, we know that he did not fill up a thousand years. We understand also that the expression, a day of the Lord is as a thousand years, coincides with this.
And, further, a man among us named John, one of the apostles of Christ, prophesied in a Revelation made to him that they who have believed our Christ will spend a thousand years in Jerusalem, and that afterwards the universal, and, in one word, eternal resurrection of all at once, will take place, and also the judgment. And this too our Lord said: They shall neither marry, nor be given in marriage, but shall be equal to angels, being children of God (that is) of the resurrection.