Catechism of the Catholic Church §577 — excerpt
At the beginning of the Sermon on the Mount Jesus issued a solemn warning in which he presented God's law, given on Sinai during the first covenant, in light of the grace of the New Covenant:
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.