Gennadius. Lives of Illustrious Men 8

Theodorus, successor to the grace and the headship of the above mentioned Abbot Pachomius, addressed to other monasteries letters written in the language of Holy Scripture, in which nevertheless he frequently mentions his master and teacher Pachomius and sets forth his doctrine and life as examples. This he had been taught he said by an Angel that he himself might teach again. He likewise exhorts them to remain by the purpose of their heart and desire, and to restore to harmony and unity those who, a dissension having arisen after the death of the Abbot, had broken the unity by separating themselves from the community. Three hortatory epistles of his are extant.