A.T. Robertson Commentary Matthew 12:44

"Then he saith, I will return into my house whence I came out; and when he is come, he findeth it empty, swept, and garnished." — Matthew 12:44 (ASV)

Into my house (εις τον οικον μου). So the demon describes the man in whom he had dwelt. "The demon is ironically represented as implying that he left his victim voluntarily, as a man leaves his house to go for a walk" (McNeile). "Worse than the first" is a proverb.