Ambrose of Milan
Catena Aurea · Lukasevangelium 11
When the unclean spirit is gone out of a man, he walketh through dry places, seeking rest; and finding none, he saith, I will return unto my house whence I came out. And when he cometh, he findeth it swept and garnished. Then goeth he, and taketh to him seven other spirits more wicked than himself; and they enter in, and dwell there: and the last state of that man is worse than the first.
The comparison then is between one man and the whole Jewish people, from whom through the Law the unclean spirit had been cast out. But because in the Gentiles, whose hearts were first barren, but afterwards in baptism moistened with the dew of the Spirit, the devil could find no rest because of their faith in Christ, (for to the unclean spirits Christ is a flaming fire,) he then returned to the Jewish people. Hence it follows, And finding none, he saith, I will return to my house whence I came.