Titus 1:15

All things are clean to the clean. That is, no creature is evil of its own nature; and the distinction of animals, clean and unclean, is now out of date, as are the other ceremonies of the Jewish law. And that to these unfaithful, defiled men, nothing is clean, because their consciences are defiled when they make use of them against their conscience. (Witham) --- St. Paul here tells Titus, to be particularly on his guard against those who wished to introduce among Christians a distinction of meats, and to preach up the necessity of divers purifications prescribed by the Mosaic law. All kinds of meats, he says, are clean to those who preserve their hearts free from sin; it is not what enters into the body defiles a man. But to eat with unwashed hands; to eat swine's flesh, or meat that has been offered to idols: these things in themselves are indifferent actions, though particular circumstances may make them criminal. (1 Corinthians viii. 4, 5, 6, &c.) (Calmet) --- But to the defiled, &c. On the contrary, the man whose soul is defiled with sin, or who lives in infidelity, never can possess purity of heart; whatever legal washings or purifications, whatever sacrifices or ceremonies of the law he may make use of, all these cannot wash away the stains of the soul. (Estius, Menochius, Tirinus)