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 Samaritan alphabet. After the fall of the Persian Empire in 330 BCE, Jews used both scripts before settling on the square Assyrian form. The square Hebrew alphabet was later adapted and used for writing languages of the Jewish diaspora – such as Karaim, the Judeo-Arabic languages, Judaeo-Spanish, and Yiddish. The Hebrew alphabet continued in use for scholarly writing in Hebrew and came again into everyday use with the rebirth of the Hebrew language as a spoken language in the 18th and 19th centuries, especially in Israel. In the traditional form, the Hebrew alphabet is an abjad consisting only of consonants,