17 It is, therefore, to be desired that renewed zeal should be called forth in the founding, enlarging, and directing of these confraternities, and that not only by the sons of St. Dominic, to whom by virtue of their Order a leading part in this Apostolate belongs, but by all who are charged with the care of souls, and notable in those places in which the Confraternity has not yet been canonically established. We have it especially at heart that those who are engaged in the sacred field of the missions, whether in carrying the Gospel to barbarous nations abroad, or in spreading it amongst the Christian nations at home, should look upon this work as especially their own. If they will make it the subject of their preaching, We cannot doubt that there will be large numbers of the faithful of Christ who will readily enrol themselves in the Confraternity, and who will earnestly endeavour to avail themselves of those spiritual advantages of which We have spoken, and in which consist the very meaning and motive of the Rosary. From the Confraternities, the rest of the faithful will receive the example of greater esteem and reverence for the practice of the Rosary, and they will be thus encouraged to reap from it, as We heartily desire that they may, the same abundant fruits for their souls' salvation.
Source: Laetitiae Sanctae (Vatican.va)