A stone was brought and placed over the entrance to the den and the king sealed it with his own personal seal and those of his nobles so that no one could interfere with what was happening to Daniel.
But God's solid, trustworthy foundation stone stands firm, with this inscription, “The Lord knows those who belong to him,” and “Everyone who calls on the name of the Lord should stay away from all that is evil.”
The angel threw him into the Abyss and shut it and sealed it over him, so that he would no longer be able to deceive the nations until the thousand years were over. After that he has to be set free for a little while.