Revelation 5:9

And they sung. new song.

It is new because it celebrates. new triumph of Christ who had been deemed worthy to hold and to open the book; that is, to control and to reveal the future, as the book is the book of the future. The song declares why he was adjudged worthy of this divine honor. It was because "he wast slain and hast redeemed" the human race.

Hast redeemed us.

Do not the four beasts and the twenty-four elders praise Christ for dying for them? They do in our translation, but according to Lange the proper translation of their song is, "Thou wast slain and has redeemed to God, out of every kindred, and tongue, and people, and nation, and hast made them unto God kings and priests; and they shall reign upon the earth." He declares that criticism has shown that the received Greek text is in this place corrupt. Lange, Alford and Tischendorf are all agreed. These intelligences praise the Lamb, not for their salvation, but for human redemption.