Encyclical of Pope Leo XIII on the Rosary, 8 September 1894.
The recourse we have to Mary in prayer follows upon the office she continuously fills by the side of the throne of God as Mediatrix of Divine grace; being by worthiness and by merit most acceptable to Him, and, therefore, surpassing in power all the angels and saints in Heaven. Now, this merciful office of hers, perhaps, appears in no other form of prayer so manifestly as it does in the Rosary. For in the Rosary all the part that Mary took as our co-Redemptress comes to us, as it were, set forth, and in such wise as though the facts were even then taking place; and this with much profit to our piety, whether in the contemplation of the succeeding sacred mysteries, or in the prayers which we speak and repeat with the lips.
First come the Joyful Mysteries. The Eternal Son of God stoops to mankind, putting on its nature; but with the assent of Mary, who conceives Him by the Holy Ghost. Then St. John the Baptist, by a singular privilege, is sanctified in his mother's womb and favored with special graces that he might prepare the way of the Lord; and this comes to pass by the greeting of Mary who had been inspired to visit her cousin. At last the expected of nations comes to light, Christ the Savior. The Virgin bears Him. And when the Shepherds and the wise men, first-fruits of the Christian faith, come with longing to His cradle, they find there the young Child, with Mary, His Mother. Then, that He might before men offer Himself as a victim to His Heavenly Father, He desires to be taken to the Temple; and by the hands of Mary He is there presented to the Lord. It is Mary who, in the mysterious losing of her Son, seeks Him sorrowing, and finds Him again with joy. And the same truth is told again in the sorrowful mysteries.
In the Garden of Gethsemane, where Jesus is in an agony; in the judgment-hall, where He is scourged, crowned with thorns, condemned to death, not there do we find Mary. But she knew beforehand all these agonies; she knew and saw them. When she professed herself the handmaid of the Lord for the mother's office, and when, at the foot of the altar, she offered up her whole self with her Child Jesus--then and thereafter she took her part in the laborious expiation made by her Son for the sins of the world. It is certain, therefore, that she suffered in the very depths of her soul with His most bitter sufferings and with His torments. Moreover, it was before the eyes of Mary that was to be finished the Divine Sacrifice for which she had borne and brought up the Victim. As we contemplate Him in the last and most piteous of those Mysteries, there stood by the Cross of Jesus His Mother, who, in a miracle of charity, so that she might receive us as her sons, offered generously to Divine Justice her own Son, and died in her heart with Him, stabbed with the sword of sorrow.
Thence the Rosary takes us on to the Glorious Mysteries, wherein likewise is revealed the mediation of the great Virgin, still more abundant in fruitfulness. She rejoices in heart over the glory of her Son triumphant over death, and follows Him with a mother's love in His Ascension to His eternal kingdom; but, though worthy of Heaven, she abides a while on earth, so that the infant Church may be directed and comforted by her "who penetrated, beyond all belief, into the deep secrets of Divine wisdom" (St. Bernard). Nevertheless, for the fulfillment of the task of human redemption there remains still the coming of the Holy Ghost, promised by Christ. And behold, Mary is in the room, and there, praying with the Apostles and entreating for them with sobs and tears, she hastens for the Church the coming of the Spirit, the Comforter, the supreme gift of Christ, the treasure that will never fail. And later, without measure and without end will she be able to plead our cause, passing upon a day to the life immortal. Therefore we behold her taken up from this valley of tears into the heavenly Jerusalem, amid choirs of Angels. And we honor her, glorified above all the Saints, crowned with stars by her Divine Son and seated at His side the sovereign Queen of the universe.
If in all this series of Mysteries, Venerable Brethren, are developed the counsels of God in regard to us--"counsels of wisdom and of tenderness" (St. Bernard)--not less apparent is the greatness of the benefits for which we are debtors to the Virgin Mother. No man can meditate upon these without feeling a new awakening in his heart of confidence that he will certainly obtain through Mary the fullness of the mercies of God.
And to this end vocal prayer chimes well with the Mysteries. First, as is meet and right, comes the Lord's Prayer, addressed to Our Father in Heaven: and having, with the elect petitions dictated by Our Divine Master, called upon the Father, from the throne of His Majesty we turn our prayerful voices to Mary. Thus is confirmed that law of merciful meditation of which We have spoken, and which St. Bernardine of Siena thus expresses: "Every grace granted to man has three degrees in order; for by God it is communicated to Christ, from Christ it passes to the Virgin, and from the Virgin it descends to us."
And we, by the very form of the Rosary, do linger longest, and, as it were, by preference upon the last and lowest of these steps, repeating by decades the Angelic Salutation, so that with greater confidence we may thence attain to the higher degrees--that is, may rise, by means of Christ, to the Divine Father. For if thus we again and again greet Mary, it is precisely that our failing and defective prayers may be strengthened with the necessary confidence; as though we pledged her to pray for us, and as it were in our name, to God.
Excerpted from Leo XIII's encylical letter on the Rosary, Iucunda semper expectatione, 8 September 1894.