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 the pronunciation of the letter and is called a "geresh". The pronunciation of the following letters can also be modified with the geresh diacritic, the represented sounds are however foreign to Hebrew phonology, i.e., these symbols mainly represent sounds in foreign words or names when transliterated with the Hebrew alphabet, and not loanwords. A "geresh" is also used to denote acronyms pronounced as a string of letters, and to denote a Hebrew numeral. Geresh also is the name of one of the notes of cantillation in the reading of the Torah, but its appearance and function is different. In Israel's