Office of the Dead

The Office of the Dead is a prayer cycle of the Liturgy of the Hours in the Roman Catholic Church, said for the repose of the soul of a deceased. It is the proper reading on All Souls' Day (normally November 2) for all souls in Purgatory, and can be a votive office on other days when said for a particular deceased. The work is composed of different psalms, scripture, prayers and other parts, divided into First Vespers, Mass, Matins, and Lauds. The editor is not known, but the office as it exists today is no older than from 7th or 8th century.

A very known refrain originating from it is "Timor mortis conturbat me", translated as "I am afraid of death, it is confounding me" or, less literarily and more appropriately, "I am scared to death of dying". – Wikipedia