Revelation 21:6; Alpha and Omega

Revelation 21:6 (KJV)  And he said unto me, It is done. I am Alpha and Omega, the beginning and the end. I will give unto him that is athirst of the fountain of the water of life freely. 

The One sitting on the throne resumes His speech in v6 – And he said unto me, It is done. I am Alpha and Omega, the beginning and the end. I will give unto him that is athirst of the fountain of the water of life freely. 

His initial announcement “It Is done” is almost identical with His Word in Revelation 16:17.

Revelation 16:17 (KJV)  And the seventh angel poured out his vial into the air; and there came a great voice out of the temple of heaven, from the throne, saying, It is done. 

The following words “I am Alpha and Omega” match what He says about Himself in Revelation 1:8 and confirm that He is the speaker at this point.

Revelation 1:8 (KJV)  I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty. 

is sovereign control over everything and His eternal nature guarantee His complete trustworthiness and the faithfulness and truthfulness of the words He has spoken. What He starts He is able to complete. He is the unchangeable One by whom the old was and the new shall be. This agrees with His earlier assessment of Himself and with Christ’s statement about Himself in Revelation 22:13 (Swete).

Revelation 22:13 (KJV)  I am Alpha and Omega, the beginning and the end, the first and the last.

[Robert L. Thomas, Revelation 8-22 – An Exegetical Commentary, Moody 1995, 448]