Commentaries
15:10-20 Christ shows that the defilement they ought to fear, was not from what entered their mouths as food, but from what came out of their mouths, which showed the wickedness of their hearts. Nothing will last in the soul but the regenerating graces of the Holy Spirit; and nothing should be admitted into the church but what is from above; therefore, whoever is offended by a plain, seasonable declaration of the truth, we should not be troubled at it. The disciples ask to be better taught as to this matter. Where a weak head doubts concerning any word of Christ, an upright heart and a willing mind seek for instruction. It is the heart that is desperately wicked, Jer 17:9, for there is no sin in word or deed, which was not first in the heart. They all come out of the man, and are fruits of that wickedness which is in the heart, and is wrought there. When Christ teaches, he will show men the deceitfulness and wickedness of their own hearts; he will teach them to humble themselves, and to seek to be cleansed in the Fountain opened for sin and uncleanness.
11. Not that which goeth into the mouth defileth a man; but that which cometh out of the mouth, this defileth a man—This is expressed even more emphatically in Mark (Mr 7:15, 16), and it is there added, "If any man have ears to hear, let him hear." As in Mt 13:9, this so oft-repeated saying seems designed to call attention to the fundamental and universal character of the truth it refers to.