“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.”
King James Version (KJV)
21:6 And he - That sat upon the throne. Said to me, It is done - All that the prophets had spoken; all that was spoken, #Rev 4:1|. We read this expression twice in this prophecy: first, #Rev 16:17|, at the fulfilling of the wrath of God; and here, at the making all things new. I am the Alpha and the Omega, the beginning and the end - The latter explains the former: the Everlasting. I will give to him that thirsteth - The Lamb saith the same, #Rev 22:17|.
Re 21:6 It is done. All things are come to pass. I am the Alpha and the Omega. See PNT "Re 1:8". This shows that the speaker is Christ.