Catechism of the Catholic Church §2149 — excerpt
Oaths which misuse God's name, though without the intention of blasphemy, show lack of respect for the Lord. the second commandment also forbids magical use of the divine name.
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: St. Augustine, De serm. Dom. in monte 2, 5, 19: PL 34, 1278