Chapter 20 — Part II: The Sacraments — Extreme Unction
Section 9. Thus its matter is most significant of what is inwardly effected in the soul by the Sacrament. Oil is very efficacious in soothing bodily pain, and the power of this Sacrament lessens the pain and anguish of the soul. Oil also restores health, brings joy, feeds light, and is very efficacious in refreshing bodily fatigue. All these effects signify what the divine power accomplishes in the sick man through the administration of this Sacrament. So much will suffice in explanation of the matter.