From the Explanations of the Psalms by Saint Ambrose, bishop

Brother cannot redeem brother, but a man will redeem man. No one can give to God the ransom for himself nor the price of his soul’s redemption. Christ is saying: What have I to fear in the day of evil? What can do me harm if I do not need a redeemer but am myself the redeemer of all mankind? Shall I free others, yet tremble for myself? See, I shall make all things new, so as to surpass even the love and devotion of brothers. Where a brother, born of the womb, cannot redeem, suffering as he does from the infirmity of a common nature, yet a man will redeem, that man of whom it is written: The Lord will send them a man who will save them; the man who said of himself: You seek to kill me, a man who has spoken the truth to you.

From a homily by Saint Amadeus of Lausanne, bishop

Observe how fitting it was that even before her assumption the name of Mary shone forth wondrously throughout the world. Her fame spread everywhere even before she was raised above the heavens in her magnificence. Because of the honor due her Son, it was indeed fitting for the Virgin Mother to have first ruled upon earth and then be raised up to heaven in glory. It was fitting that her fame be spread in this world below, so that she might enter the heights of heaven on overwhelming blessedness. Just as she was borne from virtue to virtue by the Spirit of the Lord, she was transported from earthly renown to heavenly brightness.

From a sermon by Saint Bernard, abbot

Love is sufficient of itself, it gives pleasure by itself and because of itself. It is its own merit, its own reward. Love looks for no cause outside itself, no effect beyond itself. Its profit lies in its practice. I love because I love, I love that I may love. Love is a great thing so long as it continually returns to its fountainhead, flows back to its source, always drawing from there the water which constantly replenishes it. Of all the movements, sensations and feelings of the soul, love is the only one in which the creature can respond to the Creator and make some sort of similar return however unequal though it be. For when God loves, all he desires is to be loved in return; the sole purpose of his love is to be loved, in the knowledge that those who love him are made happy by their love of him.

From the Moral Reflections on Job by Saint Gregory the Great, pope

Holy men beset by tribulation must endure the assaults of those who use violence and verbal attacks. The former they resist with the shield of patience, but against the latter they launch the sharp arrows of true doctrine. In both types of fighting they win the day through the wonderful arts that virtue bestows, for within wisdom they teach the wayward while showing a courageous contempt for outward hostility; the straying sheep they set on the right path by their teaching; the attacker they suffer and overcome. For they have nothing but patient scorn for the enemy who moves against them, but they sympathize with their weaker fellows and bring them back to the safe way, opposing the former lest they lead others astray and fearing for the latter lest they completely lose sight of the truly upright life.

From a sermon on Baptism by by Saint Pacian, bishop

As we have borne the image of the earthly man, so we shall bear the image of him who is from heaven; since the first man who came from the earth, is earthly, but the second man who came from heaven, is heavenly. And so, dearly beloved, we shall not die anymore. Even if we fall asleep in this body, we shall live in Christ, as he said: Whoever believes in me, even if he die, shall live. As the Lord is our witness, we are certain that Abraham, Isaac, Jacob and all the saints of God are alive. For concerning them the Lord says: They are all alive. For God is a God of the living, and not of the dead. And the Apostle says of himself: For me, to live is Christ and to die is gain. I would rather die and be with Christ. And again: But while we are still in this body we are away from God, for we are guided by faith, and not by appearance. This is what we believe, dearest brothers. For the rest: If we place our hope in this world, we are the most miserable of men. Life in this world, whether it be that of beasts, wild animals or birds, as you yourselves see, is either similar to ours or more tedious. What is peculiar to man, and what Christ gives through his Spirit, is eternal life, but only if we sin no more. Thus death is acquired by sin but avoided by right living; life is lost through sin and preserved through good living. The wages of sin is death; the gift of God is eternal life through Jesus Christ our Lord.

From a sermon on Baptism by by Saint Pacian, bishop

The sin of Adam had come into all men. Through one man, the Apostle says, sin entered and through sin, death. Thus it has come to all men. Therefore, the justice of Christ must enter into men; and as the old Adam ruined his descendants through sin, so Christ must bring new life to all men through justice. The Apostle stresses this theme when he says: As through the disobedience of one man, many were made sinners, so too, through the obedience of one man, many were made just. And, as sin brought death to the offender, so grace through justice brings birth to life eternal.

From the apostolic constitution Munificentissimus Deus by Venerable Pius XII, pope

In their homilies and sermons on this feast the holy fathers and the great doctors spoke of the assumption of the Mother of God as something already familiar and accepted by the faithful. They gave it greater clarity in their preaching and used more profound arguments in setting out its nature and meaning. Above all, they brought out more clearly the fact that what is commemorated in this feast is not simply the total absence of corruption from the dead body of the Blessed Virgin Mary but also her triumph over death and her glorification in heaven, after the pattern set by her only Son, Jesus Christ.