About the Mystery of the Letters the mid-6th century, in which Mar Saba had played an important role. The anonymous author of the treatise declares he was prompted to the study of the secret meanings of the letters by the words of the Apocalypse, "I am the Alpha and Omega", and that he subsequently received a vision about them on Mount Sinai. The author proposes a re-modelled Greek alphabet reduced to 22 letters on the model of the 22 letters of Hebrew (discounting Xi Ξ and Psi Ψ), and with the Hebrew letter names. He then interprets these letters as symbolic figures of 22 works of
Hebrew alphabet to the letters is the teaching of Rabbi Eliezer that the five letters of the alphabet with final forms hold the "secret of redemption". In addition, the letters occasionally feature in aggadic portions of non-mystical rabbinic literature. In such aggada the letters are often given anthropomorphic qualities and depicted as speaking to God. Commonly their shapes are used in parables to illustrate points of ethics or theology. An example from the Babylonian Talmud (a parable intended to discourage speculation about the universe before creation): Extensive instructions about the proper methods of forming the letters are found in Mishnat Soferim, within