(17) Is cast out into the draught.--The word is used in its old English meaning, as equivalent to drain, sewer, cesspool (see 2Kings 10:27). St. Mark (Mark 7:19) adds the somewhat perplexing words, "purging all meats," on which see Note on that verse. The principle implied is that a process purely physical from first to last cannot in itself bring any moral defilement. It was possible, of course, that the appetites connected with that process might bring the taint of moral evil; but then these appetites were there before the food, and they took their place among the things that came "out of the heart," and not into it.

Verse 17. - Whatsoever entereth in at the mouth, etc. Food taken into the mouth goes into the stomach, is assimilated into the bodily system, and its refuse passes away to the draught (ἀφεδρῶνα), the necessary house. It has nothing to do with the heart or the moral being; it affects only the material organization, and has no connection with the spiritual. Christ does not concern himself with questions, which modern philosophers would attempt to solve, concerning the mutual influence of soul and body, the animal and spiritual nature; he puts forth an argument which every one could receive, plain even to those "without understanding." This is the elucidation of the first part of ver. 11. The further explanation follows in vers. 18, 19.

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.Do not ye understand,.... You must understand, you cannot be so ignorant,

that whatsoever entereth in at the mouth, goeth into the belly, and is cast out into the draught? that is, that whatsoever food a man takes in at his mouth, he swallows down, and it is received into his stomach; which, having performed its office, the grosser parts go down into the belly, and passing through the bowels, are evacuated into the vault, or privy, "purging all meats", as Mark says; for that only receives the filth and excrementitious matter; so that what is left in the body is pure, wholesome, and nourishing: nor can any part of what goes into a man defile him, because it only enters into the body, and passes through it; and, as Mark says, "entereth not into the heart", which is the seat of moral impurity; so that no moral pollution can be contracted by eating any sort of food, even though it should not be clean itself, nor be eaten with clean hands.