‘And the serpent cast out of his mouth water as a river, that he might cause her to be carried away by the stream, and the earth helped the woman, and the earth opened her mouth and swallowed up the river which the monster cast out of his mouth.'
The water like a river coming from the dragon's mouth can, in the first place, be compared with the fire from the locust's mouths (Revelation 9:18). It is something spiritually destructive. An ironic contrast may be intended between believers from whose innermost being flow rivers of living water (John 7:38), and the Temple from which flowed the water of life (Ezekiel 47), and Satan from whose mouth flows a river of destructive waters. Thus it may refer to a flood of ‘false ideas' seeking to turn God's people from their faith, a flood which was somehow diverted ‘by God'.
At the time when large numbers of Jews were preparing to take up arms against the Romans tremendous pressure was being put on fellow Jews to participate in the insurrection. Christian Jews who had fled into the wilderness might indeed have been sought out to persuade them to participate, and John may even have known of a particularly nasty situation where this was prevented by some natural occurrence such as an earthquake, or by assistance from non-Christians giving them refuge. ‘The earth', in contrast to Heaven, may represent such people - for in Revelation non-Christians are ‘those who dwell on earth'. (The methods used to gain support were sometimes particularly nasty for those who were obdurate. Men can easily lose control when patriotism and religious feeling go hand in hand).
Alternatively, in Isaiah 43:2 waters and rivers are pictures of tribulation and hardship that will come on the people of God, and there He promises, ‘I will be with you --- they shall not overflow you' (compare Psalms 66:12). Thus this may refer to the waters of persecution which Satan tried to bring on those whom God was protecting. The earth is then seen as opening up to protect His people in fulfilment of His promise. Again there may be in mind non-Christian sympathetic assistance, ‘swallowing them up' and enabling them to avoid pursuers.
Alternately it may have in mind a flood of soldiers as described in Jeremiah 46:8 above. The river of Satan being likened to ‘the river of Egypt', and seeking to overwhelm the fleeing ‘Israel' as at the Exodus. The earth opening up may then be referring to some natural phenomenon that diverted the soldiers from their grim duty, as the waters of the reed sea swallowed up Pharaoh's host.
Indeed all three ideas may have been in John's mind, the river depicting Satanic attack from all sources. Apocalyptic ideas are all embracing.
The idea of the earth or ground opening up to swallow something is found in Genesis 4:11; Numbers 16:30. They have no direct connection with this passage, but possibly the seed idea may have sprung from those passages. The emphasis is on the fact that the intervention was not a direct act of God but something natural, it was the earth and not directly Heaven that intervened. Although of course God was seen as behind the deliverance.
Whichever is in the mind of John the important fact is that Satan did his worst and God protected His people.