Albert Barnes on Matthew 12:43-45

When the unclean spirit, etc. The general sentiment which our Saviour here teaches is much more easily understood than the illustration which he uses. The Jews had asked a sign from heaven that should decisively prove that he was the Messiah, and satisfy their unbelief. He replies, that though he should give them such a sign--a proof conclusive and satisfactory; and though for a time they should profess to believe, and apparently reform--yet such was the obstinacy of their unbelief and wickedness, that they would soon return to them, and become worse and worse. Infidelity and wickedness, like an evil spirit in a possessed man, were appropriately at home in them. If driven out, they would find no other place so comfortable and undisturbed as their bosoms, Everywhere they would be comparatively like an evil spirit going through deserts and lonely places, and finding no place of test. They would return, therefore, and dwell with them.

He walketh through dry places. That is, through deserts--regions of country unwatered, sandy, barren, desolate, That out Saviour here speaks according to the ancient opinions of the Jews, that evil spirits had their abodes in those desolate uninhabited regions, there can be no doubt. Nor can there be any doubt that the Bible gives countenance to the opinion. Thus Rev 18:2: "Babylon--is become the habitation of devils, and the hold of every foul spirit;" that is, has become desolate --a place where evil spirits appropriately dwell. So Isa 13:21: "And satyrs shall dance there ;" i.e., according to the ancient Greek translation, "devils, or demons, shall dance there." See also Jer 50:39. Isa 34:14. De 32:17.

Seeking rest, and findeth none, Thus desolate and dry regions are represented as uncomfortable habitations; so much so, that the dissatisfied spirit, better pleased with a dwelling in the bosoms of men, as affording an opportunity of doing evil, seeks a return there.

(r) "When the unclean" Lk 11:24 (s) "he walketh" Job 1:7, 1Pet 5:8