This book centers on a Greek text that was likely compiled in Constantinople, in 1105, for use in one of the monasteries located there. The book is a liturgical psalter, containing the fixed structure (the ordinary) in both the Greek original and in English translation, as well as a description of the hours themselves. The extensive commentary explains the development of the monastic office, and the particular history of the translated manuscript, while brief notes clarify and explain, in a way suitable for non-liturgists, the more-technical aspects of the offices.