Oecumenius

And he was cast down to the earth, either suffering this visibly, or because having been deprived of his angelic and heavenly rank, he was cast down to an earthly mindset. Then, just as one defending himself, he blames God for his downfall, since it was not possible for him to harm God himself, he harms God's servants, the people, and tries to deceive and turn them away from God, thinking that by doing this he is harming the same Master.

Commentary on Revelation ↗

Irenaeus

At present, however, I have simply been led to mention him, that thou mightest know that all those who in any way corrupt the truth, and injuriously affect the preaching of the Church, are the disciples and successors of Simon Magus of Samaria. Although they do not confess the name of their master, in order all the more to seduce others, yet they do teach his doctrines. …

Against Heresies Book I ↗

Bede

And the great dragon was cast out to the earth. The ancient enemy, expelled from the spiritual realm, is confined more tightly to the earthly realm. This is to be cast out of heaven and sent to the earth. To whom it is said: You shall eat dust all the days of your life (Genesis III). On this earth, he is trampled under the feet of the saints, as it is written: You shall tread upon the asp and the basilisk (Psalm XCI).

Commentary on Revelation ↗

Alcuin of York

And that great dragon was cast out, that old serpent, who is called the devil and Satan, who seduceth the whole world; he was cast unto the earth, and his angels were thrown down with him. Our enemy is called a dragon because of his evilness, great because of the hugeness of his wickedness, a serpent because of his snares, old because of the long duration of his deception, and devil because of his fall from heaven and his accusation of the faithful and elect: indeed, devil means both "flowing downwards" and "slanderer;" as for Satan, …

Commentary On Revelation ↗