Revelation 5:8-9

8and when he had taken the scroll, the four living creatures and the twenty-four elders threw themselves to the ground before the Lamb. Each of them had a harp and golden bowls full of incense (which are the prayers of the saints).

9They were singing a new song: “You are worthy to take the scroll and to open its seals because you were killed, and at the cost of your own blood you have purchased for God persons from every tribe, language, people, and nation.