66 But if so much consideration is needed in other churches for the ordination of a bishop, how much care is required in the Church of Vercellæ, where two things seem to be equally required of the bishop, monastic rule and church discipline? For Eusebius of holy memory was the first in Western lands to bring together these differing matters, both while living in the city observing the rules of the monks, and ruling the Church with fasting and temperance. For the grace of the priesthood is much increased if the bishop constrain young men to the practice of abstinence, and to the rule of purity; and forbid them though living in the city, the manners and mode of life of the city.
Source: Letters (New Advent)