Victorinus of Pettau — on Rev 20:6 (Commentary on the Apocalypse of the Blessed John)

“"Blessed and holy is he who has part in this resurrection: on them the second death shall have no power, but they shall be priests of God and Christ, and they shall reign with Him a thousand years." I do not think the reign of a thousand years is eternal; or if it is thus to be thought of, they cease to reign when the thousand years are finished. But I will put forward what my capacity enables me to judge. The tenfold number signifies the decalogue, and the hundredfold sets forth the crown of virginity: for he who shall have kept the undertaking of virginity completely, and shall have faithfully fulfilled the precepts of the decalogue, and shall have destroyed the untrained nature or impure thoughts within the retirement of the heart, that they may not rule over him, this is the true priest of Christ, and accomplishing the millenary number thoroughly, is thought to reign with Christ; and truly in his case the devil is bound. But he who is entangled in the vices and the dogmas of heretics, in his case the devil is loosed. But that it says that when the thousand years are finished he is loosed, so the number of the perfect saints being completed, in whom there is the glory of virginity in body and mind, by the approaching advent of the kingdom of the hateful one, many, seduced by that love of earthly things, shall be overthrown, and together with him shall enter the lake of fire.”