Chapter 33 — Part IV: Prayer — On Prayer in General
Section 58. For The Blessed Virgin Mary — To this sort of prayer belongs the first part of the Angelic Salutation, when used by us as a prayer: Hail Mary, full of grace, the Lord is with thee, blessed art thou among women. For in these words we render to God the highest praise and return Him most gracious thanks, because He has bestowed all His heavenly gifts on the most holy Virgin; and at the same time we congratulate the Virgin herself on her singular privileges.