Revelation 20:1-3

Then I saw an angel coming down from heaven, holding in his hand the key of the abyss and a heavy chain. He seized the dragon, that ancient serpent — that is, the Devil, or Satan — and chained him up for a thousand years. The angel threw him into the abyss, locked it, and sealed it, so that he could not deceive the nations any more until the thousand years were over. After that he must be let loose for a little while.