Albert Barnes on Revelation 22:7

Behold, I come quickly. Rev 1:3. The words here used are undoubtedly the words of the Redeemer, although they are apparently repeated by the angel. The meaning is, that they were used by the angel as the words of the Redeemer. See Rev 22:12, 20.

Blessed is he that keepeth the sayings of the prophecy of this book. That receives them as a Divine communication; that makes use of them to comfort himself in the days of darkness, persecution, and trial; and that is obedient to the precepts here enjoined. Rev 1:3.

(b) "quickly" Rev 22:10,12,20