Roman Catechism 20.14

Chapter 20 — Part II: The Sacraments — Extreme Unction

Section 14. Institution of Extreme Unction — Having thus proved that Extreme Unction is truly and properly to be numbered among the Sacraments, we rightly infer that it owes its institution to Christ our Lord. It was subsequently made known and promulgated to the faithful by the Apostle St. James.