12:43 “When 1 an unclean spirit 2 goes out of a person, 3 it passes through waterless places 4 looking for rest but 5 does not find it. 12:44 Then it says, ‘I will return to the home I left.’ 6 When it returns, 7 it finds the house 8 empty, swept clean, and put in order. 9 12:45 Then it goes and brings with it seven other spirits more evil than itself, and they go in and live there, so 10 the last state of that person is worse than the first. It will be that way for this evil generation as well!”
[12:43] 4 sn The background for the reference to waterless places is not entirely clear, though some Jewish texts suggest spirits must have a place to dwell, but not with water (Luke 8:29-31; Tob 8:3). Some suggest that the image of the desert or deserted cities as the places demons dwell is where this idea started (Isa 13:21; 34:14).
[12:44] 9 sn The image of the house empty, swept clean, and put in order refers to the life of the person from whom the demon departed. The key to the example appears to be that no one else has been invited in to dwell. If an exorcism occurs and there is no response to God, then the way is free for the demon to return. Some see the reference to exorcism as more symbolic; thus the story’s only point is about responding to Jesus. This is possible and certainly is an application of the passage.