Catechism of the Catholic Church

In treating the rite of Confirmation, it is fitting to consider the sign of anointing and what it signifies and imprints: a spiritual seal. (695) Anointing, in Biblical and other ancient symbolism, is rich in meaning: oil is a sign of abundance and joy; it cleanses (anointing before and after a bath) and limbers (the anointing of athletes and wrestlers); oil is a sign of healing, since it is soothing to bruises and wounds; and it makes radiant with beauty, health, and strength.