About the Mystery of the Letters
A long section of the text is devoted especially to the letter Waw and its Greek equivalent, Digamma (called Episemon in the treatise), the numeral sign for "6". This sign is interpreted as a special symbol of Christ. This idea is further connected to the interpretation of all three extra-alphabetic numeral signs of Greek ("Episemon" for 6, Koppa for 90, and Sampi for 900) as symbols of the Holy Trinity, i.e. Christ, the Holy Ghost and God the Father respectively later in the text.