Mark 7:23

all these evil things come from within, and defile the man.

The disciples had gotten into the habit of talking over the public teaching of the Lord, in order to find its true meaning, to get the full understanding. Here also they waited until Jesus came home with them, to the place where He, and, perhaps, they all were lodging at that time. Here they asked Him concerning this saying, which they call a parable, that is, in this case, an obscure saying, a comparison hard to understand. The evangelist notes the full speech of Jesus, in which He chode their lack of spiritual insight. Their stupidity is purposely made prominent, in order to bring out their need of instruction. Jesus here extends the saying, which before had touched only upon the moral sphere of man's life, in order to make His meaning still plainer. That which enters into the body from without, in the shape of food, cannot make him unclean morally or spiritually, it cannot affect the condition of his heart before God. Foods merely, generally speaking, influence the physical side of man. They are taken into the stomach, and finally the waste matter is thrown out by the body, thus actually purging the body of matter which might make him unclean. Thus Christ incidentally extended His saying concerning ceremonial uncleanness to abolishing the distinction maintained in the Old Testament concerning the cleanness and uncleanness of various foods. He practically declared all meats to be clean; the distinction which the Jews had so rigidly and rigorously observed was hereby abrogated for the New Testament.

But the lesson which Christ wanted to teach lay deeper; the physical side of the process touched upon by Him was only aside issue. That upon which all depends is the right attitude, the proper understanding of the things that go out from the body. From inside, from the heart, which is full of evil and inclined toward all evil by nature, come thoughts, desires, words, actions that defile the man. God looks into the heart. It is not only the actual sin which is culpable in His sight, but the very thoughts are bad, wrong, sinful before Him. And they all live in the heart: adulteries, open disruptions of the marriage-rights; thefts, the unlawful desire and gain of the neighbor's goods; murders, any thoughts or acts that make the neighbor's life unpleasant or destroy it; fornications, actual severing of the marriage-tie; covetousnesses, striving after goods that belong to the neighbor by God's gift or permission; wickednesses, all forms of evil dispositions; fraud, by which people try to get the best of their neighbor; debauchery, in which men serve their own bodies in a manner unbecoming Christians and human beings; an evil eye, jealousy, which begrudges the other person everything good; blasphemy, by which God is mocked and all that is holy is defiled; presumption, the lifting of one's self above the neighbor; lack of knowledge, moral foolishness. The seed, the germ of all these sins, lies in the heart of every man by nature, only awaiting the occasion when it will come forth and work havoc. These are the things that defile a person, but not any form of the so-called Levitical or ceremonial uncleanness. A Christian has need to watch over his heart unceasingly, lest any of these evil seeds sprout and grow beyond all control.