Albert Barnes Commentary Revelation 12:13

"And when the dragon saw that he was cast down to the earth, he persecuted the woman that brought forth the man [child]." — Revelation 12:13 (ASV)

And when the dragon saw that he was cast unto the earth. That is, when Satan saw that he was doomed to defeat and overthrow, as if he had been cast out of heaven; when he saw that his efforts must be confined to the earth, and that only for a limited time, he persecuted the woman, and was more violently enraged against the church on earth.

He persecuted the woman which brought forth the man child. See the notes on Revelation 12:5.

The child is represented as safe; that is, the ultimate progress and extension of the church was certain. However, Satan was still permitted to wage warfare against the church. This warfare is represented here by his wrath against the woman and by her being compelled to flee into the wilderness.

It is unnecessary to say that after the Pagan persecutions ceased and Christianity was firmly established in the empire, Satan saw that all hope of destroying the church in that manner was at an end.

Consequently, his enmity was vented in another form: the rise of the Papacy and the persecutions under it—an opposition to spiritual religion no less determined and deadly than that which had been waged by Paganism.