Eusebius of Caesarea
Patristic
c. A.D. 260–339
“Zion and Jerusalem that have the good news told them the apostle knew to be heavenly, when he said, "But the Jerusalem above is free, and she is our mother," and, "You have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to innumerable angels." Zion might also mean the church established by Christ in every part of the world, and Jerusalem the holy constitution that, once established of old time among the ancient Jews alone, was driven into the wilderness by their impiety and then again was restored far better than before through the coming of our Savior. Therefore the prophecy says, "Break forth together into singing, you waste places of Jerusalem; for the Lord has comforted his people, he has redeemed Jerusalem."Nor would you be wrong in calling Zion the soul of every holy and godly person, so far as it is lifted above this life, having its city in heaven, seeing the things beyond the world. For it means "a watchtower." And insofar as such a person remains calm and free from passion, you could call that one Jerusalem—for Jerusalem means "vision of peace."”