Catechism of the Catholic Church §2168 — excerpt
The third commandment of the Decalogue recalls the holiness of the sabbath: "The seventh day is a sabbath of solemn rest, holy to the LORD."
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.