Revelation 5:8-9

8And when he had taken the book, the four living creatures and the four and twenty elders fell down before the Lamb, having each one a harp, and golden bowls full of incense, which are the prayers of the saints. 9And they sing a new song, saying,

Worthy art thou to take the book, and to open the seals thereof: for thou wast slain, and didst purchase unto God with thy blood men of every tribe, and tongue, and people, and nation,