Catechism of the Catholic Church §2129 — excerpt
The divine injunction included the prohibition of every representation of God by the hand of man. Deuteronomy explains: "Since you saw no form on the day that the Lord spoke to you at Horeb out of the midst of the fire, beware lest you act…
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.