Roman Catechism 23.2

Chapter 23 — Part III: The Decalogue — Introduction on the Commandments in General

Section 2. Since, then, the Decalogue is a summary of the whole Law, the pastor should give his days and nights to its consideration, that he may be able not only to regulate his own life by its precepts, but also to instruct in the law of God the people committed to his care. The lips of the priest shall keep knowledge, and they shall seek the law at his mouth, because he is the angel of the Lord of hosts. To the priests of the New Law this injunction applies in a special manner; they are nearer to God, and should be transformed from glory to glory, as by the Spirit of the Lord. Since Christ our Lord has called them light, it is their special duty to be a light to them that are in darkness, the instructors of the foolish, the teachers of infants; and if a man be overtaken in any fault, they who are spiritual should instruct such a one.