Catechism of the Catholic Church §582 — excerpt
Going even further, Jesus perfects the dietary law, so important in Jewish daily life, by revealing its pedagogical meaning through a divine interpretation: "Whatever goes into a man from outside cannot defile him.
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.
Whole chapters cited: Numbers 28