John Cassian, The Institutes IV.1

Of the training of those who renounce this world, and of the way in which those are taught among the monks of Tabenna and the Egyptians who are received into the monasteries.

From the canonical system of Psalms and prayers which ought to be observed in the daily services throughout the monasteries, we pass, in the due course of our narrative, to the training of one who renounces this world; endeavouring first, as well as we can, to embrace, in a short account, the terms on which those who desire to turn to the Lord can be received in the monasteries; adding some things from the rule of the Egyptians, some from that of the monks of Tabenna, whose monastery in the Thebaid is better filled as regards numbers, as it is stricter in the rigour of its system, than all others, for there are in it more than five thousand brethren under the rule of one Abbot; and the obedience with which the whole number of monks is at all times subject to one Elder is what no one among us would render to another even for a short time, or would demand from him.