Alpha and Omega
"I the LORD, the first, and with the last, I am he"--Isaiah 41:4
"Thus saith the LORD the King of Israel, and his redeemer the LORD of hosts; I am the first, and I am the last; and beside me there is no God"--Isaiah 44:6
"Hearken unto me, O Jacob and Israel, my called; I am he; I am the first, I also am the last"--Isaiah 48:12
Alpha is used by the Jews for the chief of persons or things; 'Macmas and Mezonicha [names of places] are "Alpha for fine flour"'; that is, the best fine flour is there, they are the chief places for it...these letters...being the first and the last in the alphabet, may stand for the whole; and it seems to be a proverbial expression taken from the Jews, who use the phrase, from Aleph to Tau, for the whole of any thing... [Jesus] stands in the first verse of Genesis, and in the last of the Revelation.
The New John Gill's Exposition of the Entire Bible