Charles Spurgeon Commentary Matthew 15:18

"But the things which proceed out of the mouth come forth out of the heart; and they defile the man." — Matthew 15:18 (ASV)

But those things which proceed out of the mouth come forth from the heart; and they defile the man.

The main matter to be considered is the heart, not the mouth, and other parts of the body. Note how our Lord, by this great truth, puts the axe to much that looks very fair and appeared good, and cuts it down as worthless. If we serve God with the heart, there is the core of true religion; but if not, we may have as many ceremonial washings as there are hours in the day and days in the year, and we may be careful to avoid this article of diet and to feed on that, to wear this garment and not to wear that, and to observe this day and not that; but all this outward religion will be of no avail whatever, if our heart is not savingly affected by the grace of God.

The expressions of the mind come from the soul of a person and possess a moral character, things which proceed out of the mouth come forth from the heart. Words, the thoughts that wear words as their garments, and the acts that are the embodiment of words—these come from the person themselves, and these defile them.

If the mind or heart had nothing to do with an act, it would no more pollute a person than the food that they swallow and expel. Because acts and words come not only from the mouth but from the soul, they are of far more importance than food and drink. Of course, defilement comes to a person when they are guilty of gluttony and drunkenness; yet this is not because of the mere food or drink, but because consuming them to excess is the exercise of unbridled appetite, and this appetite also grows by what gratifies it.