The development of liturgical prayers in any tradition involves many and varied sources, and the Syriac traditions are no exception. In the present essay, Anton Baumstark publishes a Latin translation of nineteen prayers of the Eastern Syriac tradition found in Bedjan’s Chaldean Breviary and discusses the possible textual influences on these prayers from previous literature, including the Psalms, the Apostolic Constitutions, and various Syriac patristic authors. Baumstark’s translations of the hymns (qâlê) include critical notes with direct comparisons to the other pieces of literature that Baumstark discusses in the introduction.