1 And I saw an angel coming down out of Heaven, having the key of the abyss, and a great chain upon his hand.
Revelation 20:1 Cross References - Worrell
Luke 8:31
31 And they were entreating Him, that He would not command them to go away into the abyss.
2 Peter 2:4
4 For, if God spared not angels that sinned, but, hurling them down to Hell, delivered them up to pits of darkness, kept for judgment;
Jude 1:6
6 And angels who kept not their own principality, but left their proper habitation, He hath kept in everlasting bonds, under darkness, for the judgment of the great day.
Revelation 1:18
18 and the Living One; and I was dead; and, behold, I am alive forevermore; and I have the keys of death and of Hades.
Revelation 9:1-2
1 And the fifth angel sounded, and I saw a star fallen out of the heaven to the earth, and there was given to him the key of the pit of the abyss.
2 And he opened the pit of the abyss; and there went up a smoke out of the pit, as the smoke of a great furnace; and the sun and the air were darkened by reason of the smoke of the pit.
Revelation 10:1
1 And I saw another strong angel, descending out of Heaven, clothed with a cloud, and the rainbow was upon his head, and his face was as the sun, and his feet as pillars of fire.
Revelation 18:1
1 After these things I saw another angel coming down out of Heaven, having great authority; and the earth was illumined with his glory.