Rev 20:1-3

The Thousand Years 1Then I saw an angel coming down from heaven, holding in his hand the key to the bottomless pit and a great chain.2He seized the dragon, that ancient serpent, who is the Devil and Satan, and bound him for a thousand years,3and threw him into the pit, and locked and sealed it over him, so that he would deceive the nations no more, until the thousand years were ended. After that he must be let out for a little while.