Catechism of the Catholic Church §2538 — excerpt
The tenth commandment requires that envy be banished from the human heart. When the prophet Nathan wanted to spur King David to repentance, he told him the story about the poor man who had only one ewe lamb that he treated like his own daughter…
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. John Chrysostom, Hom. in 2 Cor. 27, 3-4 PG 61, 588