Revelation 20:7

For these nations which he names Gog and Magog are not to be understood of some barbarous nations in some part of the world, whether the Getæ; and Massagetæ;, as some conclude from the initial letters, or some other foreign nations not under the Roman government. For John marks that they are spread over the whole earth,

And thus the reign of the saints with Christ shall last longer than the bonds and imprisonment of the devil, because they shall reign with their King the Son of God for these three years and a half during which the devil is no longer bound. So that we understand either that the thousand years of the reign of the saints does not terminate, though the imprisonment of the devil does,— so that both parties have their thousand years, that is, their complete time, yet each with a different actual duration approriate to itself, the kingdom of the saints being longer, the imprisonment of the devil shorter, — or at least that, as three years and six months is a very short time, it is not reckoned as either deducted from the whole time of Satan's imprisonment, or as added to the whole duration of the reign of the saints, as we have shown above in the sixteenth book regarding the round number of four hundred years, which were specified as four hundred, though actually somewhat more; and similar expressions are often found in the sacred writings, if one will mark them.

And when he says that when the thousand years are ended, that is, when the Lord, having fulfilled the economy of his flesh, has returned to the heavens, the bonds of the spiritual powers will be loosed from the Devil, and again he will deceive the nations; for it has been said in what has been spoken before that the Lord's presence among men abolishes the activity of the Devil. But since the Lord has ascended into the heavens, it is the Devil who will exercise his ordinary and habitual powers, and those on earth will use their free will as they used to; for the Devil endeavors to deceive all. Some, however, are persuaded, while others, by resisting, contend against the evil one.

But one might perhaps say: and why, being somewhat restrained and hindered in his natural impulse by the bodily presence of the Lord, was the Devil nevertheless allowed once more to deceive those on earth? For would it not have been better that he be bound, and that men remain unled astray? To this it must be replied: why do you rather ask of him the origin, how the Devil came into being, than, having come and transgressed, why he was not utterly destroyed, so that no opportunity against men might remain to him? And how, then, sir, were the contestants trained if there was no opponent at all? And how, moreover, was the strength of the athletes shown if there was no rival? For the careless are inferior in men and in pleasures, and, with no Devil present to incite them, are altogether foolish on their own; but those who are men of God and brave contestants would be wronged if their courage against the passions were not made public; as happens, that the careless gain nothing when Satan is absent, and the zealous are most greatly wronged. For Satan is in a manner a trainer of men, providing an occasion of crowns to those who struggle. For the sinful, who even without the presence of the Devil, through their own negligence make use of him instead of the Devil, are not even wronged, as has been said. Therefore, he benefits some unwillingly, and does no wrong to others, or very little. But you wished through me and you, the "slaves of sin" (Rom. 6:16) and stripped and fallen, that we be deprived by the activity of the Devil of the glory of patriarchs and prophets, of apostles and evangelists and those who endured even to blood for the witness of Christ and kept what is genuine for him, moreover of confessors and those shepherds esteemed good for the churches and the most steadfast abstainers and all that is righteous and perfected in the faith of Christ, "of whom this world is not worthy." (Heb. 11:38) So that the brave champions of virtue console the punishment of sinners whose brief crimes are judged, for one who succeeds is to be preferred by the God, even when ten thousand reject Him.

Both therefore were brought about in the fairest and most inspired manner, and that in the Lord's presence the impious impulses of the Devil were cut off, and after the Lord's ascent into heaven he was loosed for the testing of men. For if Satan had been allowed to display all his power while the Lord was dwelling on earth, he would not have permitted men even to be hearers of His divine teaching or to learn who is by nature and in truth God, or what religion is acceptable to Him, or what wickedness and what virtue are; indeed he would have prepared the cross for Him beforehand and begun it even before the teaching. Were this to happen, the incarnation of the Lord and so great and so honorable a mystery would have been incomplete and, rather, useless. But after these things were taught on earth under the bondage of the Devil, men were left thereafter to use their own free will and to contend with the adversary by means of those confessed and unknown ways of wickedness and of virtue. For he who knows the good and the not-good, by self-willed impulses chooses one thing or the other at any cost; but he who is ignorant of what he should do, as one wounded in a night-battle and unaware even that he has been struck, does not even know his own ruin. For in the case of one who has knowledge of opposites there is room for self-choice to select what he wishes, but for the ignorant there is no room. God made man free from the beginning and governed him by sovereign planning.

That it is necessary first to know virtue and vice, so that the land may therefore be subject to free choice, see what Moses says to the disobedient people of Israel in Deuteronomy: "Behold, I have set before you this day life and death, the good and the evil," (Deut. 30:15) that you may surely choose the thing which is preferred; and again the same in Exodus: "If you will indeed listen to the voice of my words and do them, he says, all that I shall say to you." (Ex. 23:32) And what says Isaiah, of whom the same teaching is cited at the beginning of his prophecy, speaking from the presence of God: "If you will and will hear me, you shall eat the good of the land; but if you will not and will not hear me, the sword will devour you; for the mouth of the Lord has spoken these things." (Isa. 1:19-20)

[We have here a difficulty] for we must inquire how it is that when the thousand years have ended, the enemy is given his freedom and the nations [continue to] live upon the earth within that infinity [which occurs after the end]. For indeed, after the resurrection, when the judgment of the living and the dead has been rendered, all things everlasting are given and those who reign with Christ, namely, the saints, will come with God’s aid to the eternal blessings, that is, to the very reality of eternality itself. Moreover, they will be rewarded with the contemplation of him who is the Beginning, and possessing the presence of a vision of such a majesty they will be established in its bliss. When the rewards of all the blessed have been consummated and perfected, and all things have been brought to the one headship of our Lord Jesus Christ and in him all things are held together, “Satan will be loosed from his prison.” Then the nether regions themselves will be freed from him, at the same time the author of darkness will be dissolved and disappear, “and go out,” into eternal perdition.

Some interpret the period of a thousand years to be the three and a half years from the baptism of Christ to his ascension into heaven, and they believe that after this the devil is to be loosed. Others say that after the completion of six thousand years the first resurrection of the dead will occur for the saints alone, so that on this very earth on which they endured suffering, they might enjoy temporal largess and glory for a thousand years, and that after this [period] the general resurrection will occur, which will be not only of the righteous but also of the sinners. It is unnecessary to say that the church receives nothing of this.Rather, we listen to the Lord when he says to the Sadducees that the righteous will be “as the angels in heaven.” We listen also to the apostle who says, “the kingdom of God is not food and drink.” And so we interpret the thousand-year period to be that of the preaching of the gospel.… It is not necessary to think of these thousand years in terms of a number. When it is said in the Song of Songs “everyone was to bring for its fruit a thousand pieces of silver,” and again, “Solomon shall have a thousand and they who keep its fruit two hundred,” the precise number is not indicated, but the full and complete harvest. So also here, the harvest of faith in its entirety is meant, after which “the son of perdition, the man of lawlessness” will come “so that all may be condemned who did not believe the truth but had pleasure in unrighteousness,” as the apostle says. And the Lord said, “I have come in my Father’s name, and you do not receive me; another will come in his own name, him you will receive.”

It must be known that Ezekiel also prophesied that thèse nations will come in the end times with great power to fall upon the land of Israël and that their weapons are to be burnt for seven years through a great fire, which on the one hand, some of the interpreters took (to mean) the fall of the Assyrians with Sennacherib having occurred many years ago at the time of Hezekiah during the prophecy of Ezekiel (2Kgs 19:35), but on the other hand, some (interpret it as) the destruction of the nations attacking those who undertook to rebuild Jérusalem after her capture by the Babylonians,(Theodore) first Cyrus the Persian, and after him Darius having commanded so to the governors of Syria. And some see it as meaning the powers of Antiochus having been defeated by the Maccabees.

From the Hebrew language some interpret Gog as "one who gathers" or "gathering" and Magog "proud." Through the names is to be signified either the gathering of the nations or arrogance.

And when the thousand years are completed, etc. He said completed as part of a whole, for he will be released such that three years and six months of the last struggle will remain. But besides this trope, it is rightly said that the time is finished. For such small remnants are not to be counted, since seven hundred and as many years as God wills are called an hour by the apostle.

For Gog is interpreted as 'covered', and Magog as 'uncovered'.

sand of the sea. And this is said as a figure of speech not intended to be taken literally.

By Gog, which means ‘roof.’ Antichrist is understood, who will be the dwelling place of the Devil. By Magog, which means ‘from the roof,’ those who follow Antichrist are understood, as has been said more fully in Ez. 39.

the four quarters of the earth. that is, from all parts of the earth.