The Twelve Books on the Institutes of the Cœnobia, and the Remedies for the Eight Principal Faults

For we have found that many in different countries, according to the fancy of their mind, have made for themselves different rules and arrangements in this matter. For some have appointed that each night twenty or thirty Psalms should be said, and that these should be prolonged by the music of antiphonal singing, and by the addition of some modulations as well. Others have even tried to go beyond this number. Some use eighteen. And in this way we have found different rules appointed in different places, and the system and regulations that we have seen are almost as many in number as the monasteries and cells which we have visited. There are some, too, to whom it has seemed good that in the day offices of prayer, viz., Tierce, Sext, and Nones, the number of Psalms and prayers should be made to correspond exactly to the number of the hours at which the services are offered up to the Lord. Some have thought fit that six Psalms should be assigned to each service of the day. And so I think it best to set forth the most ancient system of the fathers which is still observed by the servants of God throughout the whole of Egypt, so that your new monastery in its untrained infancy in Christ may be instructed in the most ancient institutions of the earliest fathers.