Revelation 10:4

And I heard a voice from heaven — Doubtless from him who had at first commanded him to write, and who presently commands him to take the book; namely, Jesus Christ. Seal up those things which the seven thunders have uttered, and write them not — These are the only things of all which he heard that he is commanded to keep secret: so something peculiarly secret was revealed to the beloved John, besides all the secrets that are written in this book. At the same time we are prevented from inquiring what it was which these thunders uttered: suffice that we may know all the contents of the opened book, and of the oath of the angel.