Contradiction with Amos 3:7
Amos 3:7 suggests that God reveals His secrets to His prophets, while Revelation 10:8 implies a message might remain sealed.
Amos 3:7: Surely the Lord GOD will do nothing, but he revealeth his secret unto his servants the prophets.
Contradiction with Matthew 24:36
Matthew 24:36 states that no one knows the day or hour of certain events, contrasting with the revelation given in Revelation 10:8.
Matthew 24:36: But of that day and hour knoweth no [man], no, not the angels of heaven, but my Father only.
Contradiction with Daniel 12:9
Daniel 12:9 mentions that words are closed up and sealed until the end time, which could seemingly contradict the open revelation in Revelation 10:8.
Daniel 12:9: And he said, Go thy way, Daniel: for the words [are] closed up and sealed till the time of the end.