The Canons of the Council in Trullo; Often Called The Quinisext Council 29Canon XXIX.

A canon of the Synod of Carthage says that the holy mysteries of the altar are not to be performed but by men who are fasting, except on one day in the year on which the Supper of the Lord is celebrated. At that time, on account perhaps of certain occasions in those places useful to the Church, even the holy Fathers themselves made use of this dispensation. But since nothing leads us to abandon exact observance, we decree that the Apostolic and Patristic tradition shall be followed; and define that it is not right to break the fast on the fifth feria of the last week of Lent, and thus to do dishonour to the whole of Lent.