{21} And the earth helped the woman, and the earth opened her mouth, and swallowed up the flood which the dragon cast out of his mouth.

(21) That is, there was offered in their place other Jews, to the Romans and nations raging against that people: and it came to pass by this that the Church of God was saved entirely from that violence, that most raging flood of persecution which the dragon vomited out being completely exhausted in the destroying of those other Jews.

People's New Testament

12:16 The earth helped the woman. In some way the flood of persecution was so hindered that it failed to accomplish the object. I believe this refers to the hindrances often interposed by secular powers to stay persecution. The Hussites protected themselves under Zisca by force of arms; the German princes protected Luther; the edict of Nantes gave French Protestants a rest. These were times when the earth drank up the flood.

Matthew Henry's Concise Commentary

12:12-17 The church and all her friends might well be called to praise God for deliverance from pagan persecution, though other troubles awaited her. The wilderness is a desolate place, and full of serpents and scorpions, uncomfortable and destitute of provisions; yet a place of safety, as well as where one might be alone. But being thus retired could not protect the woman. The flood of water is explained by many to mean the invasions of barbarians, by which the western empire was overwhelmed; for the heathen encouraged their attacks, in the hope of destroying Christianity. But ungodly men, for their worldly interests, protected the church amidst these tumults, and the overthrow of the empire did not help the cause of idolatry. Or, this may be meant of a flood of error, by which the church of God was in danger of being overwhelmed and carried away. The devil, defeated in his designs upon the church, turns his rage against persons and places. Being faithful to God and Christ, in doctrine, worship, and practice, exposes to the rage of Satan; and will do so till the last enemy shall be destroyed.