Do you not yet understand, that whatsoever enters in at the mouth goes into the belly, and is cast out into the drain?
All Commentaries on Matthew 15:17 Go To Matthew 15
Chromatius of Aquileia
The Pharisees, as Peter made clear, begrudgingly grasped the dictum of the Lord which says, “It is not what enters the mouth that defiles a man.” God indicated through Moses long ago that not everything about the use of food must be considered clean. He declared that certain things were clean and other things were unclean. But now we must ask why God prohibited the people long ago to eat these things. Since all things created by God to be used as human food were blessed at the very beginning and they remain no less so by their very nature, why is it that divine law later prescribed to the Jewish people certain things as lawful for eating because they were clean and certain things as unlawful because they were unclean? First, precepts of this type were given by the Lord because of the dissipation and immoderate appetite of the people. For since they were overly concerned with eating and drinking, these people began to overlook God’s precepts. They made for themselves a molten calf in Horeb, about which it was written, “The people sat down to eat and drink and rose up to play.” Those necessary things were forbidden by the Lord, so that with the best food having been denied and their immoderate appetites mortified, the people might abide more easily by the discipline of divine observance. It was only after their disobedience with the molten calf that we find those things were prohibited. Concerning them, as though to rebuke this stiffnecked people, the Lord made a mild and merciful pronouncement: “They shall be unclean to you.” Not that they are in themselves unclean, but “shall be.” Nor did he say “to all” but “to you.” He thus made it clear that neither were they unclean nor would they be unclean to people other than themselves. And certainly they deserved this prohibition of many foods, for these people preferred the meats of Egypt, as well as cucumbers and muskmelons, to heavenly manna.