Catechism of the Catholic Church §1173 — excerpt
When the Church keeps the memorials of martyrs and other saints during the annual cycle, she proclaims the Paschal mystery in those "who have suffered and have been glorified with Christ.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: SC 104 · SC 108, 111