These ten verses together describe the complete demise of the serpent that instigated human revolt against God in Genesis 3:1–7. Revelation 20:1–3 tells us of his arrest and imprisonment. Revelation 20:7–10 relates his short-term release and God’s final judgment over Satan and his lackeys. Between these two bookends, the Holy Spirit has placed a paragraph relating the exalted position granted to those who resisted the dragon and his beasts during their earthly sojourn (Revelation 20:4–6).
1 Then I saw an angel coming down from heaven, holding in his hand the key to the bottomless pit and a great chain.