Council of Trent: Session XXII, Sacrifice of the Mass, Chapter III

CHAPTER III. On Masses in honour of the Saints.

And although the Church has been accustomed at times to celebrate, certain masses in honour and memory of the saints; not therefore, however, doth she teach that sacrifice is offered unto them, but unto God alone, who crowned them; whence neither is the priest wont to say, "I offer sacrifice to thee, Peter, or Paul;" but, giving thanks to God for their victories, he implores their patronage, that they may vouchsafe to intercede for us in heaven, whose memory we celebrate upon earth.

Translation: J. Waterworth, The Canons and Decrees of the Council of Trent (1848), Hanover Historical Texts Project transcription (1995).