Albert Barnes on Matthew 12:44

Then he saith, I will return into my house, etc. The man is called his house, because he had been the place where the spirit had dwelt.

He findeth it empty, etc. There is here the continuance of the reference to the dwelling of the spirit in men. He was called his house. By the absence of the evil spirit, the house is represented as unoccupied, or empty, swept, and garnished; that is, while the evil spirit was away, the man was restored to his right mind, was freed from his wicked influence.

Garnished. Adorned, put in order, furnished. Applied to the man, it means that his mind was sane and regular when the evil spirit was gone; or, he had a lucid interval.