The article presents the Syriac text of the fragment from the treatise «On Monastic Life» by the West Syrian theologian Athanasios Abu Ghalib (d. 1177), with Russian translation, introduction and commentaries. Athanasios Abu Ghalib was bishop of Jihan and created his works in the period of the «Syriac Renaissance». His writing «On Monastic Life» was not edited and translated up to now. The Syriac text is prepared according to two manuscripts: MS Mingana syr. 118 (20th c.) и MS Mosul 34 (18th c). In the introduction is analyzed the specific of the genre of the Syriac work, its language and rhetoric. There is characterized the way of using of different biblical and non-biblical sources by the Syriac author. In the introduction is also discussed the main topics of the work, e. g., the role of the admonition and punishment in the monastic community, the teaching about ascetism and others. The author emphasizes the importance of this work as a source of theology, ascetism, monasticism, rhetoric of the West Syrian Christian tradition of 12th century.