ALPHA and OMEGA (A and O), the first and last letters of the Greek alphabet, corresponding to the Aleph and Taw of the Hebrew. They are used as a designation of Himself by the speaker in Rev.i.8; xxi. 6; xxii. 13. The first and last letters of the Hebrew alphabet are used in Rabbinic writings in a similar way. We find also "the seal of God is Emeth," Emeth (truth) being composed of the first, middle and last letters of the Hebrew alphabet. God is thus represented as the beginning, middle and end of all things (see the Jewish Encyclopaedia, s.v.).
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)