About the Mystery of the Letters
The text was originally written in Palaestina Prima. It was written in the Greek language. The Coptic manuscripts names its author as Apa Seba (Arabic: Saba), referring to Saint Sabas of Palestine (439–532).  Evidence from the text itself  leads to a somewhat later dating: in the second half of the 6th century. It could have been written by a follower of Sabas, possibly a monk in the monastery of Mar Saba. This monastery had been founded by Sabas. A certain anti-philosophical polemic tendency expressed by the text can be related to the Origenist controversies of the mid-6th century, in which Mar Saba had played an important role.