Eschatology : The Binding of Satan at the End of the Tribulation.

Rom 16:20  And before long, God, the Giver of peace will crush Satan under your feet. The grace of our Lord Jesus Christ be with you! WNT

Rev 20:1  Then I saw an angel coming down from Heaven, having the key of the bottomless pit, and upon his arm he carried a great chain.

Rev 20:2  He laid hold of the Dragon--the ancient serpent--who is the Devil and the Adversary, and bound him for a thousand years, and hurled him into the bottomless pit.

Rev 20:3  He closed the entrance and put a seal upon him in order that he might be unable to lead the nations astray any more until the thousand years were at an end. Afterwards he is to be set at liberty for a short time. WNT

We have here, I. A prophecy of the binding of Satan for a certain term of time, in which he should have much less power and the church much more peace than before. The power of Satan was broken in part by the setting up of the gospel kingdom in the world; it was further reduced by the empire's becoming Christian; it was yet further broken by the downfall of the mystical Babylon; but still this serpent had many heads, and, when one is wounded, another has life remaining in it. Here we have a further limitation and diminution of his power. Observe, 1. To whom this work of binding Satan is committed - to an angel from heaven.

2. The means he makes use of in this work: he has a chain and a key, a great chain to bind Satan, and the key of the prison in which he was to be confined. Christ never wants of proper powers and instruments to break the power of Satan, for he has all the powers of heaven and the keys of hell.

3. The execution of this work, Rev_20:2, Rev_20:3. above

(1.) He laid hold on the dragon, that old serpent, which is the devil, and Satan. Neither the strength of the dragon, nor the subtlety of the serpent, was sufficient to rescue him out of the hands of Christ; he caught hold, and kept his hold. And, (2.) He cast him into the bottomless pit, cast him down with force, and with a just vengeance, to his own place and prison, from which he had been permitted to break out, and disturb the churches, and deceive the nations; now he is brought back to that prison, and there laid in chains. (3.) He is shut up, and a seal set upon him. Christ shuts, and none can open; he shuts by his power, seals by his authority; and his lock and seal even the devils themselves cannot break open. (4.) We have the term of this confinement of Satan - a thousand years, after which he was to be loosed again for a little season. The church should have a considerable time of peace and prosperity, but all her trials were not yet over. Matthew Henry’s Commentary on the Whole Bible