Charles Ellicott Commentary Revelation 20:2

"And he laid hold on the dragon, the old serpent, which is the Devil and Satan, and bound him for a thousand years," — Revelation 20:2 (ASV)

And he laid hold on the dragon . . .—Or, And he laid hold of the dragon, the ancient serpent, who is the devil and Satan, and bound him a thousand years. The four words are thus used to describe the archenemy; they are the same as those used for the same purpose in Revelation 12:9.

Over the world he has exercised his power everywhere as prince of this world, and he has been found fierce as the dragon, subtle as the serpent, the slanderer of God and His people, and the adversary of all righteousness. He is bound as Christ declared (Matthew 12:29).

A thousand years was the duration that Rabbis had fixed for Messiah’s kingdom. The period is not to be understood literally (see next verse).