9 Having learned these things, and been fully assured that the seeming bread is not bread, though sensible to taste, but the Body of Christ; and that the seeming wine is not wine, though the taste will have it so, but the Blood of Christ; and that of this David sung of old, saying, And bread strengthens man's heart, to make his face to shine with oil, “strengthen your heart,” by partaking thereof as spiritual, and “make the face of your soul to shine.” And so having it unveiled with a pure conscience, may you reflect as a mirror the glory of the Lord, and proceed from glory to glory, in Christ Jesus our Lord:— To whom be honour, and might, and glory, for ever and ever. Amen.
Source: Catechetical Lectures (New Advent)