Adam Clarke on Matthew 8:14

Peter's house - That Peter lived at Capernaum, and that Christ lodged with him, is fully evident from this verse compared with Mat 17:24.

Peter's - wife's mother - Learn hence, says Theophylact, that marriage is no hinderance to virtue, since the chief of the apostles had his wife. Marriage is one of the first of Divine institutions, and is a positive command of God. He says, the state of celibacy is not Good, Gen 2:18. Those who pretend to say that the single state is more holy than the other slander their Maker, and say in effect, "We are too holy to keep the commandments of God."