Although liturgical concerns are evident in the two martyrologies, there is no strictly contemporary evidence for Máel Ruain's own monastic principles and practices. Evidence for his teachings and their influence comes chiefly by way of a number of 9th-century writings associated with the Tallaght community known collectively as the 'Tallaght memoir'. One of the principal texts is "The Monastery of Tallaght" (9th century), which claims to list the precepts and habits of Máel Ruain and some of his associates, apparently as remembered by his follower Máel Díthruib of Terryglass. Much of the text survives in a 15th-century manuscript, RIA MS 1227 ("olim" MS 3 B 23), and in the 17th century, an Early Modern Irish paraphrase was produced now referred to as "The Teaching of Máel Ruain". Of less certain origin is the text known as the "Rule of Céli Dé", which is preserved in the Leabhar Breac (15th century) and contains various instructions for the regulation and observance of monastic life, notably in liturgical matters. It is ascribed to both Óengus and Máel Ruain, but the text in its present form is a prose rendering from the original verse, possibly written in the 9th century by one of his community. These works of guidance appear to have been modelled on the sayings of the Desert Fathers of Egypt, in particular the "Conferences" of John Cassian. Typical concerns in them include the importance of daily recitation of the Psalter, of self-restraint and forbearance from indulgences in bodily desires and of separation from worldly concerns. Against the practices of earlier Irish monastic movements, Máel Ruain is cited as forbidding his monks to go on an overseas pilgrimage, preferring instead to foster communal life in the monastery.