Revelation 5:2

and I saw a mighty angel who was proclaiming in a loud voice-- 'Who is worthy to open the book and break its seals?'

Revelation 5:5

But one of the Councillors said to me--'Do not weep. The Lion conquered--the Lion of the tribe of Judah, the Scion of David--and can therefore open the book with its seven seals.'

Revelation 18:21

Then a mighty angel took up a stone like a great millstone, and threw it into the sea, crying-- 'So shall Babylon, the Great City, be violently overthrown, never more to be seen.

Revelation 10:1

Then I saw another mighty angel, descending from Heaven. His robe was a cloud; over his head was the rainbow; his face was like the sun, and his feet like pillars of fire;

Treasury of Scripture Knowledge

Summary

And I saw a strong angel proclaiming with a loud voice, Who is worthy to open the book, and to loose the seals thereof?

Bible References

Who

Revelation 5:5
But one of the Councillors said to me--'Do not weep. The Lion conquered--the Lion of the tribe of Judah, the Scion of David--and can therefore open the book with its seven seals.'