Charles Ellicott Commentary Matthew 12:43

"But the unclean spirit, when he is gone out of the man, passeth through waterless places, seeking rest, and findeth it not." — Matthew 12:43 (ASV)

When the unclean spirit is gone out of a man — The parable is introduced abruptly, possibly because here, as elsewhere, we have only part of a discourse. It seems to be a collection of striking passages, arranged now in this order, now in that, with the connecting links missing. However, the inner connection of thought is clear enough. One might ask how Israel had sunk to such a depth of evil, and the answer is found in the parable that follows.

The phenomena that provide the basis for the comparison were likely familiar enough. Insofar as possession shared characteristics with insanity, there could be sudden and violent relapses after periods of calm and apparent cure. The spirit of the person, influenced by exorcisms, prayers, or the sympathy of friends, might assert its freedom for a time, only to yield again to the oppressor. In the story of such a demoniac, which our Lord narrates using the language of popular belief, He sees a parable for the history of the Jewish people.

Walketh through dry places — This description reflects the popular idea that the parched deserts of Syria, Arabia, and Egypt were haunted by demons, who came from there to invade the bodies and souls of men. For example, in the book of Tobit, the demon Asmodeus flees to the upper regions of Egypt .