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
Phoenician alphabet Cyrillic script was derived from the Greek alphabet. Some Cyrillic letters (generally for sounds not in Mediaeval Greek) are based on Glagolitic forms, which in turn were influenced by the Hebrew or even Coptic alphabets. The Latin alphabet was derived from Old Italic (originally a form of the Greek alphabet), used for Etruscan and other languages. The origin of the Runic alphabet is disputed, and the main theories are that it evolved either from the Latin alphabet itself, some early Old Italic alphabet via the Alpine scripts or the Greek alphabet. Despite this debate, the Runic alphabet is clearly derived