Catechism of the Catholic Church §1551 — excerpt
This priesthood is ministerial. "That office . . which the Lord committed to the pastors of his people, is in the strict sense of the term a service."
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: LG 24 · St. John Chrysostom, De sac. 2, 4: PG 48, 636