Revelation 10:8

And the voice which I heard from heaven, I heard it again speaking with me, and saying, Go, take the book which is open in the hand of the angel that standeth upon the sea and upon the earth.

The voice from heaven ... is a frequent reference in this prophecy. Although no definite speaker is identified here, the message is to be understood as coming from God.

Go take the book which is open in the hand of the angel ... Hinds pointed out that, "John himself now becomes a part of the scene,"[38] a very important truth to remember when we come to interpret Revelation 10:11.

Which is open ... It is nothing less than amazing that this fact of the book's being open, and continuing so, which is so repeatedly emphasized in this chapter should be so completely ignored by so many writers. For example, Wilbur M. Smith wrote, '"The little book which John is told to take and eat is never opened; and hence its exact nature must be a matter of dispute."[39]

Go take ... This command was repeated in Revelation 10:9, where its repetition has the effect of denying John's request that the angel "give" him the little book, and symbolizing the profound truth that the word of God must, in a sense, be taken by every man for himself. Some other person cannot give to any man the knowledge and understanding of the word of God that he should exercise himself to acquire. "Study to show thyself approved unto God!"

[38] John T. Hinds, op. cit., p. 150.

[39] Wilbur M. Smith, Wycliffe Bible Commentary, New Testament (Chicago: Moody Press, 1971), p. 1074.