Augustine of Hippo

When there is forgiveness of sins through the sacraments, the house is cleaned; but the Holy Spirit must be a necessary inhabitant. And the Holy Spirit inhabits only those who are humble of heart, for God says, "Upon whom will my Spirit rest?" And he answers the question: "Upon the one who is humble and quiet and who fears my word." Therefore, when he is the inhabitant, he fills up, rules, acts, deters from evil, inspires one to do good and tempers justice with sweetness, so that one may do good with the love of an upright heart and …

Sermon 72A.2 ↗

Jerome

And coming, he finds it empty, swept clean, and put in order. Then he goes and takes with him seven other spirits more wicked than himself, and they enter and dwell there; and the last state of that man becomes worse than the first. So it will be with this wicked generation. For the temple of the Jews was empty, and it did not have Christ as a guest, who said: Rise, let us go from here (John 14:31). And in another place: Your house shall be left to you desolate (Luke 13:35). …

Commentary on Matthew ↗

Thomas Aquinas

Then he goes and brings with him seven other spirits more evil than himself. Here he deals with the second and more serious harassment. It is shown to be more serious, first, as to the number; secondly, as to duration; thirdly, as to effect. As to number, because he brings seven. According to Chrysostom the literal explanation is that when anyone falls and is not careful, something worse happens to him: "See, you are well! Sin no more, that nothing worse befall you" (Jn 5:14). …

Commentary on Matthew ↗