And when he had taken it, the four living creatures and the twenty-four elders fell down before the Lamb. Each one had a harp and they were holding golden bowls full of incense, which are the prayers of God's people.
NIV
And when He had taken the scroll, the four living creatures and the twenty-four elders [of the heavenly Sanhedrin] prostrated themselves before the Lamb. Each was holding a harp (lute or guitar), and they had golden bowls full of incense (fragrant spices and gums for burning), which are the prayers of God's people (the saints).
AMP
And when he had taken the book, the four beasts and four and twenty elders fell down before the Lamb, having every one of them harps, and golden vials full of odours, which are the prayers of saints.
KJV