Inspired by the Holy Ghost and instructed by the Blessed Virgin, Saint Dominic preached the rosary for the rest of his life. The holy rosary, which he prayed every day, was his preparation for every sermon. He preached it by his example as well as by his sermons. He preached in cities and in country places, to people of high station and low, before scholars and the uneducated, to Catholics and to heretics. One day he was to preach at Notre Dame in Paris. It happened to be the feast of St. John the Evangelist. He was in a little chapel behind the high altar prayerfully preparing his sermon by saying the rosary, as he always did, when Our Lady appeared to him and said: “Dominic, even though what you have planned to say may be very good, I am bringing you a much better sermon.”
Saint Dominic took in his hands the book Our Lady proffered. He read the sermon carefully and when he had understood it and meditated on it; he gave thanks to her. When the time came, he went up into the pulpit and in spite of the feast day, made no mention of Saint John other than to say that he had been found worthy to be the guardian of the Queen of Heaven. The congregation was made up of theologians and other eminent people who were used to hearing unusual and polished discourses. Saint Dominic told them that it was not his desire to give them a learned discourse, wise in the eyes of the world, but rather that he would speak in the simplicity of the Holy Ghost and with His forcefulness. So he began preaching the holy rosary and explained the Hail Mary word by word as he would to a group of children. He used the very simple illustrations which were in the book given him by Our Lady.
Blessed Alan, according to Carthagena, mentioned several other occasions when Our Lord and Our Lady appeared to Saint Dominic to urge him and inspire him to preach the holy rosary more and more in order to wipe out sin and to convert sinners and heretics. In another passage Carthagena says, “Blessed Alan said Our Lady revealed to him that, after she had appeared to Saint Dominic, her blessed Son appeared to him and said, Dominic, I rejoice to see that you are not relying on your own wisdom and rather than seek the empty praise of men, you are working with great humility for the salvation of souls.
Priests should try to kindle a love of prayer in people’s hearts and especially a love of my Angelic Psalter. If only they would all start praying it and would really persevere, Almighty God in His mercy could hardly refuse to give them His grace. So I want you to preach my holy rosary.”
The Confraternity of the Holy Rosary only retained its first fervor for a century after it was instituted by Saint Dominic.
After this it was like a thing buried and forgotten. Doubtless, too, the wicked scheming and jealousy of the devil were largely responsible for getting people to neglect the holy rosary, and thus block the flow of grace which it had drawn upon the world. (St. Louis Marie De Montfort)