CCC 1450

"Penance requires . . . the sinner to endure all things willingly, be contrite of heart, confess with the lips, and practice complete humility and fruitful satisfaction."⁴⁹ Roman Catechism II, V, 21; cf. Council of Trent (1551): DS 1673DS — Denzinger–Schönmetzer (Enchiridion Symbolorum).