What does Revelation 22:10 mean?

The prophet Daniel was informed that his "words [were] shut up and sealed until the time of the end" (Daniel 12:9), but John was told not to seal the words of the prophecy of Revelation (Revelation 22:10). For Daniel, innumerable events needed to transpire before his prophecy would be fully meaningful. For John's Revelation, no events needed to occur because the time was near. He had seen or heard everything relevant which would take place in the end time. Even if specific details were unclear, or yet to be fully realized, the message was ready for mankind to hear and understand.

No one knows when the Lord will return (Matthew 24:36), but the doctrine of imminence (Revelation 22:7) teaches the rapture could occur at any moment (1 Thessalonians 4:13–18). We don't have to wait for any signs to be fulfilled to recognize this as the next major event in God's timeline. The signs Jesus mentioned in Matthew 24 primarily occur after the rapture, in the tribulation, before Jesus returns to earth in a blaze of glory (Revelation 19:11–16).