It follows then that the celebration of this sacrifice be, in its proportion, an instrument of applying the proper sacrifice to all the purposes for which it was first designed. It is ministerially, and by application, an instrument propitiatory; it is eucharistical; it is an homage and an act of adoration, and it is impetratory, and obtains for us and for the whole church, all the benefits of the sacrifice, which is now celebrated and applied...
Source: wiktionary