Catechism of the Catholic Church §1329 — excerpt
The Lord's Supper, because of its connection with the supper which the Lord took with his disciples on the eve of his Passion and because it anticipates the wedding feast of the Lamb in the heavenly Jerusalem.
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.