'Seals' in the Bible

And I saw lying in the right hand of Him who sat on the throne a book written on both sides and closely sealed with seven seals.

And I saw a mighty angel who was exclaiming in a loud voice, "Who is worthy to open the book and break its seals?"

one of the Elders said to me, "Do not weep. The Lion which belongs to the tribe of Judah, the Root of David, has triumphed, and will open the book and break its seven seals."

And now they sing a new song. "It is fitting," they say, "that Thou shouldst be the One to take the book And break its seals; Because Thou hast been offered in sacrifice, And hast purchased for God with Thine own blood Some out of every tribe and language and people and nation,

And when the Lamb broke one of the seven seals I saw it, and I heard one of the four living creatures say, as if in a voice of thunder, "Come."