'Thousand' in the Bible

Then I looked, and I heard the voice of many angels around the throne and [the voice] of the living creatures and the elders; and they numbered myriads of myriads, and thousands of thousands (innumerable),

Twelve thousand were sealed from the tribe of Judah, twelve thousand from the tribe of Reuben, twelve thousand from the tribe of Gad,

twelve thousand from the tribe of Asher, twelve thousand from the tribe of Naphtali, twelve thousand from the tribe of Manasseh,

twelve thousand from the tribe of Simeon, twelve thousand from the tribe of Levi, twelve thousand from the tribe of Issachar,

twelve thousand from the tribe of Zebulun, twelve thousand from the tribe of Joseph, and twelve thousand from the tribe of Benjamin were sealed (marked, redeemed, protected).

The number of the troops of cavalry was twice ten thousand times ten thousand (two hundred million); I heard the number of them.

And in that [very] hour there was a great earthquake, and a tenth of the city fell and was destroyed; seven thousand people were killed in the earthquake, and the rest [who survived] were overcome with terror, and they glorified the God of heaven [as they recognized His awesome power].

And he overpowered and laid hold of the dragon, that old serpent [of primeval times], who is the devil and Satan, and bound him [securely] for a thousand years (a millennium);

and the angel hurled him into the abyss, and closed it and sealed it above him [preventing his escape or rescue], so that he would no longer deceive and seduce the nations, until the thousand years were at an end. After these things he must be liberated for a short time.

And then I saw thrones, and sitting on them were those to whom judgment [that is, the authority to act as judges] was given. And I saw the souls of those who had been beheaded because of their testimony of Jesus and because of the word of God, and those who had refused to worship the beast or his image, and had not accepted his mark on their forehead and on their hand; and they came to life and reigned with Christ for a thousand years.

The rest of the dead [the non-believers] did not come to life again until the thousand years were completed. This is the first resurrection.

Blessed (happy, prosperous, to be admired) and holy is the person who takes part in the first resurrection; over these the second death [which is eternal separation from God, the lake of fire] has no power or authority, but they will be priests of God and of Christ and they will reign with Him a thousand years.

And when the thousand years are completed, Satan will be released from his prison (the abyss),