Roman Catechism 7.12

Chapter 7 — Part I: The Creed — Article V: He Descended into Hell; the Third Day He Rose Again from the Dead

Section 12. To Liberate The Just — Having explained these things, the pastor should next proceed to teach that Christ the Lord descended into hell, in order that having despoiled the demons, He might liberate from prison those holy Fathers and the other just souls, and might bring them into heaven with Himself. This He accomplished in an admirable and most glorious manner; for His august presence at once shed a celestial lustre upon the captives and filled them with inconceivable joy and delight. He also imparted to them that supreme happiness which consists in the vision of God, thus verifying His promise to the thief on the cross: This day thou shalt be with me in paradise.