By Fr. William P. Saunders
Article taken from : Catholic Herald
On Holy Thursday morning, the bishop, joined by the priests of the diocese, gather at the Cathedral of St. Thomas More to celebrate the chrism Mass. This Mass manifests the unity of the priests with their bishop. Here the bishop blesses three oils – the oil of catechumens (oleum catechumenorumor oleum sanctorum), the oil of the infirm (oleum infirmorum) and holy chrism (sacrum chrisma) – which will be used in the administration of the sacraments throughout the diocese for the year. This tradition is rooted in the early Church as noted in the Gelasian Sacramentary (named after Pope Gelasius I, d. 496), but was later absorbed into the Holy Thursday evening Mass; Pope Pius XII issued a new Ordinal for Holy Week, which reinstituted a special Mass of the chrism distinct from the evening Mass.