Chapter 19 — Part II: The Sacraments — Penance
Section 118. The scrupulous care which in the primitive ages of the Church guarded the right of the ordinary priest is easily seen from the ancient decrees of the Fathers, which provided that no Bishop or priest, except in case of great necessity, presume to exercise any function in the parish of another without the authority of him who governed there. This law derives its sanction from the Apostle when he commanded Titus to ordain priests in every city, to administer to the faithful the heavenly food of doctrine and of the Sacraments.