At once I understood: It is a mystery of God which is <contained> in the letters of the alphabet, and one which he has not revealed to us!
Tractate About the Mystery of the Letters, Introduction, 21-23.
Background to the Treatise
The treatise About the Mystery of the Letters is dated to the second half of the sixth century and its author is believed to be „among the monks of a Sabaite community, possibly the most important among them, the Great Laura Mar Saba near Jerusalem, which still exists today.“  The work explores „the secret messages of the Greek alphabet.“ Its content is built on the basic idea „that there is an original connection between writing and creation.“ And „that not only in the form and shape of the letters is the mystery of Christ revealed, but also in their names and their namings. „ Thus, the author writes, „A mystery of God it is that is in the letters of the alphabet.“ And that Christ says, „I am the Alpha and the O. That is, He who is described by the whole alphabet.“
The title of the work in Greek is:
Περὶ τοῦ μυστηρίου τῶν γραμμάτων
Peri tou mysteriou ton grammaton
About the mystery of the letters
 Cordula Bandt, Der Traktat „Vom Mysterium der Buchstaben“ (Berlin 2007), (n. 33), 7.
 Bandt (n. 33) 1.
 Bandt (n. 33) 2.
 Mysterium der Buchstaben, Kap. 23.12-14, Übersetzung Bandt (n. 33) 157.
 Mysterium der Buchstaben, Vorrede, 21-22 (koptischer Teil), Übersetzung Bandt (n. 33) 103.
 Mysterium der Buchstaben, Kap. 36.12-13, Übersetzung Bandt (n. 33) 159.