15 May God, "who is rich in mercy" ( Ephes .ii., 4), benignly speed this restoration of the human race in Jesus Christ for "it is not of him that willeth, or of him that runneth, but of God that showeth mercy" ( Rom . ix., 16). And let us, Venerable Brethren, "in the spirit of humility" ( Dan . iii., 39), with continuous and urgent prayer ask this of Him through the merits of Jesus Christ. Let us turn, too, to the most powerful intercession of the Divine Mother - to obtain which We, addressing to you this Letter of Ours on the day appointed especially for commemorating the Holy Rosary, ordain and confirm all Our Predecessor's prescriptions with regard to the dedication of the present month to the august Virgin, by the public recitation of the Rosary in all churches; with the further exhortation that as intercessors with God appeal be also made to the most pure Spouse of Mary, the Patron of the Catholic Church, and the holy Princes of the Apostles, Peter and Paul.
Source: E Supremi (Vatican.va)