And I saw an angel descending from heaven, holding the key of the abyss and a great chain in his hand.
References for Revelation 20:1
And he seized the dragon--the ancient serpent, who is the devil and Satan--and bound him [for] a thousand years,
and threw him into the abyss, and shut [it] and sealed [it] above him, in order that he could not deceive the nations again until the thousand years are completed. After these [things] it is necessary [for] him to be released [for] a short time.
And I saw thrones, and they sat down on them, and authority to judge was granted to them. And [I saw] the souls of those who had been beheaded because of the testimony about Jesus and because of the word of God, and who had not worshiped the beast or his image, and did not receive the mark on their forehead and on their hand, and they came to life and reigned with Christ [for] a thousand years.
References for Revelation 20:4
(The rest of the dead did not come to life until the thousand years were completed.) This [is] the first resurrection.
Blessed and holy [is] the one who has a part in the first resurrection. Over this person the second death has no authority, but they will be priests of God and of Christ, and they will reign with him a thousand years.
References for Revelation 20:6