5:13 And every created thing which is in heaven and on the earth and under the earth and on the sea, and all things in them, I heard saying, "To Him who sits on the throne, and to the Lamb, be blessing and honor and glory and dominion forever and ever."

And every created thing which is in heaven and

All creation -- Psalm 103:19-22.

on the earth and under the earth and on the sea,
and all things in them I heard saying,

Originally, all living creatures were placed under Adam's dominion (Genesis 1:28); were confirmed with Noah (Genesis 9:8-11); BUT because of sin, Romans 8:18-22, we all wait for this moment of redemption (taking the book in Revelation 5).

It is interesting to note that this confession is coming from "created things". Today, we have little understanding how ALL of God's creation is waiting to make this confession. For example, how will a rock give Him glory? how will a chunk of ice bestow honor? how will we do this?

"To HIM who sits on the THRONE and to the LAMB, be

  1. blessing and
  2. honor and
  3. glory and
  4. dominion forever and ever."

The sound comes from everywhere, even as the whole creation was implored to praise Him -- Psalm 148:7-13.

In this verse, we see how beautifully John blends together the worship of the Father (Revelation 4) and the worship of the Son, Lamb (verses 8-12 this chapter).