Augustine of Hippo

"And he cast him into the abyss,"—i.e., cast the devil into the abyss. By the abyss is meant the countless multitude of the wicked whose hearts are unfathomably deep in malignity against the Church of God; not that the devil was not there before, but he is said to be cast in thither, because, when prevented from harming believers, he takes more complete possession of the ungodly. For that man is more abundantly possessed by the devil who is not only alienated from God, but also gratuitously hates those who serve God... But by the chain and prison-house of this interdict the devil is prohibited and restrained from seducing those nations which belong to Christ, but which he formerly seduced or held in subjection. For before the foundation of the world God chose to rescue these from the power of darkness, and to translate them into the kingdom of the Son of His love, as the apostle says.