Revelation 22:2

The river of life sets forth that the grace of spiritual doctrine flowed through the minds of the faithful, and that manifold flourishing forms of odours germinated therein. The tree of life on either bank sets forth the Advent of Christ, according to the flesh, who satisfied the peoples wasted with famine, that received life from One by the wood of the Cross, with the announcement of God's word.

'And whose leaves never fade.' [Psalm 1:3] The leaves of this tree are by no means useless. Even if one understands Holy Writ only as history, he has something useful for his soul. We read in the Apocalypse of John (a book which, although rejected in these regions, we ought nevertheless to know, because it is accepted and held as canonical throughout the west, and in other Phoenician provinces, and in Egypt, for the ancient churchmen, including Irenaeus, Polycarp, Dionysius, and other Roman expounders of Sacred Scripture, among whom is holy Cyprian, accept and interpret it): 'Behold, I saw a throne set up, and one Lamb and a tree alongside a river, and on both sides of the river was that tree.' [Revelation 22:1-2] This means that the tree 'was both on this side and on that side of the river. 'And this tree,' he says, 'bore fruit and was yielding its twelve fruits for the year according to each month. And it had lean's, too, and the leaves for the healing of the nations.' [Revelation 22:2]

'I saw,' he says, 'a single throne set up.' We believe in the Father, and the Son, and the Holy Spirit, that is true, and that they are a Trinity; nevertheless the kingship is one. 'I saw a single throne set lip, and I saw a single Lamb standing in the presence of the throne.' [Revelation 5:6] This refers to the Incarnation of the Savior. Scripture says: 'Behold the lamb of God, who takes away the sin of the world' [John 1:29] 'And there was a fountain of water coming forth from beneath the middle of the throne' [Revelation 22:1] Notice that it is from the midst of the throne that there issues forth a river of graces. That river does not issue forth from the throne unless the Lamb is standing before it, [Revelation 7:17] for unless we believe in the Incarnation of Christ, we do not receive those graces.

A tree, he says, one lofty tree had been set up. He did not say trees, but only one tree. If there is but one tree how can it be on both sides of the river? If he had said, I saw trees, it would have been possible for some trees to be on one side of the river and other trees on the other side. Actually, one tree is said to be on both sides of the river. One river comes forth from the throne of God - the grace of the Holy Spirit - and this grace of the Holy Spirit is found in the river of the Sacred Scriptures. This river, moreover, has two banks, the Old Testament and the New Testament, and the tree planted on both sides is Christ. During the year, this tree yields twelve fruits, one for each month, but we are unable to receive the fruits except through the apostles. If one approaches the tree through the apostles, he must receive the fruit; he gathers the fruit from the Sacred Scriptures; he grasps the divine meaning abiding within the words. If, therefore, one comes to this tree through the apostles, he gathers its fruit just as we have said. If, indeed, he cannot pluck the fruit, it is because he is still too weak; he is not yet a disciple, but belongs to the throng; he is an outsider, a stranger from the nations. Because he cannot pluck the fruit, he plucks only words, the leaves for the healing of the nations, for it is written: 'and the leaves are for the healing of the nations.' One who belongs to the nations, who is not a disciple, who is as yet only one of the crowd, gathers only leaves from the tree; he receives from Scripture plain words for a healing remedy. Briefly, then, the Scripture says: 'and the leaves of the tree are for the healing of the nations'; in other words, the leaves are medicine. Why have we digressed on the Apocalypse? Simply became of that tree 'that yields its fruit in due season, and whose leaves never fade. Whatever he does, prospers.'

It is speaking of the cross of the Lord. There is no tree that bears fruit in every season except the cross that the faithful, who are made wet by the water of the church’s river, eat. And these [faithful] in turn produce eternal fruit in every season.

And of the river he says that on this side and on that side there was a tree of life bearing fruit each month. The Lord calls the tree of life, according to what is written by the Proverbs writer concerning wisdom; he says "the tree of life is for all who hold fast to it." (Prov. 3:18) But Paul handed over to us "Christ as God's power and God's wisdom." (1 Cor. 1:24) And he says that not only do the saints possess the riches of Christ's gifts, but they also have and share in him dwelling within them; which is the head of the highest blessedness. But the tree of life is continuous, Christ, and unceasingly brings to completion fruits and gifts to the saints, as if to overtake zeal with zeal and lest they ever be deprived of divine flow.

And he says the leaves of the tree are for the healing of the nations. Leaves of life are the patriarchs attached to Christ and holding him, prophets, apostles, evangelists, martyrs and confessors, and those who in due times officiate at the gospel and pastors of the church, and every righteous soul; who even now heal souls, and to the saints will be an addition of good things.

By the twelve months he signifies all of time, and to be sure all of eternity. Therefore, where there is an eternal paradise, no aridity will ever be permitted to intrude. Where there is a perfect and certain well-being, absolutely no infirmity enters in. This is what the prophet promised when he said, “They shall obtain joy and gladness, and sorrow and sighing shall flee away.” This is the tree, as we read, which is “planted by streams of water,” and of which Jeremiah says that it “sends out its roots by the stream.” This is to say that it places its hope and trust in the Lord. We may also interpret this passage concerning the river of the water of life to refer to the Lord Jesus Christ, who is himself the fountain of life. For we read of him, “With you is the fountain of life; in your light we shall see light.” He is himself, as we read, “the image of God’s majesty, who is powerful in all things, and remaining in himself renews all things and in every generation rests in holy souls.” And so he is the Fountain who is also the River. He is the Fountain, for he remains in himself inexhaustible, and he is the River because he offers himself generously and perpetually so that the saints might receive of [his] abundance. Where he is called fountain, he is also called a rushing stream. When the psalm says, “You shall give them drink from the river of your delights,” it then continues, “for with you is the fountain of life, and in your light shall we see light.” Moreover, [it says that it flows] through the middle of the street for it is a good that is common to all the saints and that is not denied to any who are worthy, nor is it granted to any who are unworthy.… Indeed, it is in their midst as an undivided patrimony to all who see God. For that reason we read, “Jerusalem, a city whose fellowship is complete within itself.” If the fruit is understood to be the reward of a blissful immortality, then we rightly understand the leaves to be the song of perpetual praise, because for those who sing they fall in the well-being of a happy fate. For there exists the true healing of the nations, there is full redemption, there is eternal happiness.

Concerning wisdom it is said, “She proclaims outside; she raises her voice in the streets, and she cries out on the top of the walls.” And should anyone refuse to come to the marriage of the king, she commands her servants and says, “Go to the streets and byways and invite whomever you meet to the wedding, that my house might be filled.” This water of salvation and the cleansing of grace is described as flowing in the streets.… The two banks of the river are the two Testaments in which the fullness of our salvation is written down. There is the tree of life. There is told [the story] of our Lord Jesus Christ, who is the tree of life: “Through him we live, move, and have our being.” The leaves are his words; they are of use for the health of all nations. The twelve months are the apostles of the Lord, because the Lord himself is the “favorable year of forgiveness.” These are the twelve months, each bringing to the many the fruit of unending preaching out of an abundance of knowledge.

This river waters the saints who are planted alongside it. They are here figuratively called the “tree of life” by virtue of their participation and imitation of him who is the Tree of Life. Moreover, they give forth “twelve fruits,” that is, they unceasingly yield the production of fruit. For there will be there no winter of sin that causes the trees of life to shed their leaves, such as we see now. Rather, the time of the production of fruit by the saints will be complete and uninterrupted, and [this time] is here said to be twelve months. It speaks in these terms equally because of the customary year among us, as well as because of the proclamation of the twelve apostles. This present passage may also be interpreted in another way. “The river” might signify the gifts of the life-giving Spirit, which flow down from the throne of the Father and of the Son, that is, from the ranks of the cherubim, among whom God is enthroned. [This river flows] into the streets of the city, that is, to the full citizenry of the saints, as coming from the first ranks into the second that are made to share in the well-ordered arrangement of the heavenly hierarchy. The “tree of life” signifies Christ, whom we know by the Holy Spirit and through the Spirit. For in him is the Spirit, and he is worshiped in Spirit, and he is the supplier of the Spirit, and through him the twelve fruits of the apostolic chorus give to us the inexhaustible fruit of the knowledge of God, through whom “the acceptable year of the Lord and the day of recompense” foretold by the prophet is proclaimed to us.

The “leaves of the tree,” namely, of Christ, are the more exalted understandings of the divine judgments, even as its “fruits” are the more perfect knowledge that is to be revealed in the age to come. The leaves will be for healing, that is, for the cleansing of the ignorance of those who have been deficient in the exercise of the virtues, for “there is one glory of the sun, and another glory of the moon, and another glory of the stars.” Moreover, “in my Father’s house there are many rooms,” so that one is accounted worthy of less and another of more brightness according to the measure of the works of each. This present passage may also be interpreted otherwise. The “tree of life” produces twelve fruits, namely, the apostolic chorus that shares in him who is truly the Tree of Life, who through his participation in the flesh has given us to share in his deity. Their fruits are those who yield fruit a hundredfold. The leaves are those who yield sixtyfold. These carry to those who come later the illumination of the divine light that they had received from those who had yielded a hundredfold, and they bring healing to those from the nations who yield thirtyfold. For at that time there will be a difference between those who are saved as great as there is a difference between fruit and leaves. Some will be glorified to a lesser extent, some to a greater extent, as it is written. It writes of a “tree” in the singular rather than “trees” in the plural to indicate the unity and harmony of the life which the saints have together.

Bearing twelve kinds of fruits, yielding its fruit every month. In the twelve months, it insinuates all the time of life, namely, that where it is said: And your years will not fail (Ps. CI). And again: From month to month and from Sabbath to Sabbath (Isa. LXVI). Where the face of the Lord is present, eternal health, eternal food of life. It can also be simply understood that through the doctrine of the twelve apostles, the cross of Christ bears fruit.

And the leaves of the tree were for the healing of the nations. If the fruit is taken as the reward of blessed immortality, rightly the leaves are understood as the perpetual song, which falls for the healing of those already singing in happy lot. For there, the true healing of the nations, complete redemption, and eternal happiness.

And on either side of the river was the tree of life. The tree of life is seen around the fountain of life. Whether you interpret it as the glory of the holy cross or the Lord Christ, it is revealed both before baptism in the Old Testament and now, with the mystery of baptism shining, it nourishes the saints with heavenly fruit. For there is no other name under heaven given among men by which we must be saved (Acts IV). The same tree, which John described as flowering in the golden Jerusalem, Moses described in paradise, and Solomon said it is a tree of life to those who embrace it. I believe that this river prefigured the Jordan, beyond which Moses gave the people instructions of salvation, and within which Jesus opened the promised land.