Updated: May 9, 2019
Verse 8: (Is. 41:4; 44:6; 48:12; Rev. 1:17; 2:8; 21:6; 22:13; 1:11) I am Alpha and Omega, the beginning and the ending, saith the Lord, (Rev. 1:4; 4:8; 11:17; 16:5) which is, and which was, and which is to come, the Almighty.
[I am Α and Ω] In some manuscripts, Α καὶ τὸ Ω, not incorrectly. For Ἄλφα was wont to be pronounced whole in this sense, but Ω was thus pronounced. Ausonius, The Ω is reckoned to be the last of the Greek letters. For μέγα was not wont to be added, as neither μικρὸν to ό, nor ψιλόν to έ or ύ (Grotius). This is spoken proverbially concerning Him who is first in anything (Pareus out of Erasmus) [or last]. Thus in Martial, the Alpha of those wearing traveling coats, or of Mendicants, that is, the most beggarly one (Pareus). And Christ indeed is the greatest, but how would He be called the last (Beza)? Response: He who is the greatest is the same as the humblest, abased below all, Philippians 2:6; Ephesians 4:9, crucified, 1 Corinthians 2:8 (Cocceius). An epexegetical expression is attached next (Piscator, similarly Beza). But I distinguish this from what follows (Cocceius, similarly Cotterius), as a thing more general from a thing more specific (Cocceius). And the letters are simpler than the words; ά and ώ designate the first beginning and the final end (Cotterius). Now, it is an expression taken from the Rabbis (Grotius), who say from א/Aleph to ת/Tau (Grotius, Drusius), or from beginning to end, as in Jalkut, etc. John adjusted this to the Greek Alphabet, for he was writing in Greek (Grotius).
[The beginning (or, that is, the beginning [Beza, Piscator, Tirinus, etc.]) and the ending] Either, with respect to causality: or rather, with respect to duration, from a comparision both with Revelation 22:13, where this is repeated and the first and the last is added; and with Isaiah 41:4 and 43:10, where it is, before me, and after me, there is no God (Pererius). The sense: There is nothing before Him or after Him (Estius, similarly Piscator, Cotterius, Beza). Others: What he means by this expression the things that follow teach, namely, that God always is and was the same, and hence the certainty of His promises: what was formerly signified by יְהוָֹה/Jehovah and אֲשֶׁר יִהְיֶה, He who is. See what things were said on Exodus 3:15 and 6:3. And add Isaiah 41:4; 44:6; 48:12. Plato, Ὁ μὲν δὴ Θεὸς, ὥσπερ καὶ ὁ παλαιὸς λόγος· ἀρχήν τε καὶ τελευτὴν, καὶ μέσα τῶν ὄντων ἁπάντων ἔχων, Now, the God, even as the ancient word, holds the beginning and the ending, and the middle of all beings (Grotius). Others: He renders here the cause of that saying, Behold, He comes with the clouds. Even so, Amen; that is to say, As I am the first of all things, and created all, so I am the end unto which all will come to be judged (Menochius out of Ribera): the beginning and the ending, that is, from whom and to whom are all things (Cocceius, similarly Cluverus). He here ascribes to Himself absolute perfection, divinity (Pareus), immutability (Durham), and eternity (Pareus, Durham, Cotterius). At the same time He admonishes that we, seeking nothing outside of Him, rest in Him (Cotterius). By Α and Ω He understands the beginning and end of Sacred Scripture (Rupertus in Cluverus); that is to say, the Author, and the end and scope, of the Sacred Scriptures, which begin from me, and end in me (Cluverus).
Α/Alpha and Ω/Omega are the first and last letters in the Greek alphabet, as א/Aleph and ת/Tau are in the Hebrew alphabet: the meaning of these is expounded, the beginning and the ending; he who was before all, and shall continue to exist when all creatures shall cease to be; the first and the last, as the same terms are expounded, Revelation 22:13: so Isaiah 41:4; 43:10.
[Saith the Lord] Who? Response 1: The whole Trinity, which was inspiring in John those words, Behold, He comes, etc. (Ribera, Menochius). Response 2: Christ (Piscator, Pareus, Louis Cappel, Cotterius, Cocceius, Durham, Alcasar, Gomar, Cluverus out Primasius, Rupertus, etc.), as is demonstrated by, 1. His epithet, κύριος/Lord (Pareus); 2. the connection with the preceding verse (Cocceius, thus Pareus); 3. a comparison with Revelation 1:11, 13, 17, 18 (Cluverus, thus Louis Cappel, Pareus); 2:8 (Cluverus); 22:13, where Christ expressly says this concerning Himself (Louis Cappel, Pareus).
[Which is, and which was, etc.] The same as in verse 4 (Erasmus, thus Grotius, Menochius).
[The Almighty] Not without cause is this added. For with respect to men it comes to pass that promises are not fulfilled either through inconstancy, or through impotence: wherefore both are to be removed from God (Grotius).
Which is, and which was, and which is to come, the Almighty: see Revelation 1:4: He addeth the Almighty, to show that he was able to make his words good. Thus in this verse, omnipotency, eternity, and immutability, are all applied to God, and particularly predicated of our Lord and Saviour Jesus Christ.
 Greek: Ἐγώ εἰμι τὸ Α καὶ τὸ Ω, ἀρχὴ καὶ τέλος, λέγει ὁ Κύριος, ὁ ὢν καὶ ὁ ἦν καὶ ὁ ἐρχόμενος, ὁ παντοκράτωρ.
 The Textus Receptus and Codex Alexandrinus read τὸ Α καὶ τὸ Ω. However, the majority of texts in the Byzantine tradition read τὸ Ἄλφα καὶ τὸ Ὦ.
 Decimius Magnus Ausonius (c. 310-395) was a Latin poet and rhetorician, and a native of Burdigala (now Bourdeaux, France).
 Technopaegnion 14.
 The letter Ω/omega was not wont to be written with the μέγα/mega, but simply with the Ω/o.
 The letter ό/omicron was not wont to be written with the μικρὸν/micron, but simply with the ό/o.
 The letter έ/epsilon was not wont to be written with the ψιλὸν/psilon, but simply with the έ/e; the letter ύ/upsilon, not with the ψιλὸν/psilon, but simply with the ύ/u.
 Marcus Valerius Martialis was a first century Roman poet.
 Epigrams 5:26.
 Yalkut Shimoni is an aggadic compilation on the books of the Old Testament. Its authorship is uncertain.
 Exodus 3:15b: “…Jehovah (יְהוָה), the God of your fathers, the God of Abraham, the God of Isaac, and the God of Jacob, hath sent me unto you: this is my name for ever, and this is my memorial unto all generations.”
 Exodus 6:3: “And I appeared unto Abraham, unto Isaac, and unto Jacob, by the name of God Almighty, but by my name Jehovah (יְהוָה) was I not known to them.”
 Laws 715.