Jesus shows that the real problem is not unwashed hands but an unclean heart. Human traditions become sinful when they override God’s clear commands, and true defilement comes from the evil that rises from within a person.

The conflict begins when Pharisees and scribes from Jerusalem confront Jesus because His disciples eat with unwashed hands. That detail gives the scene an official and serious tone. Mark makes clear that the issue is not ordinary cleanliness but ritual washing tied to the tradition of the elders. The dispute, then, is about religious practice and authority, not basic table manners.

Jesus answers by quoting Isaiah. He says these leaders are like the people Isaiah rebuked: they honor God with their lips, but their heart is far from Him. Their worship is empty because they teach human commands as though they were God’s commands. Jesus is not rejecting Scripture or the law of Moses. He is exposing the way these leaders set aside the command of God in order to hold fast to human tradition.

He then gives a clear example. Moses commanded people to honor their father and mother, and Scripture treats dishonoring parents as a serious sin. Yet the leaders allowed a person to say that his resources were corban, meaning devoted to God, and then use that religious claim to avoid helping his parents. In practice, a sacred formula became a tool for disobedience. That is why Jesus says they nullify the word of God by their tradition. The problem is not tradition in every sense, but tradition that cancels what God has plainly commanded.

From there, Jesus moves from that specific case to the deeper issue of defilement. He tells the crowd that a person is not defiled by what enters from outside, but by what comes out from within. The saying is short, forceful, and somewhat puzzling, so later the disciples ask Him about it in private.

Jesus explains that food enters the stomach, not the heart, and then passes through the body. Food, therefore, does not make a person morally unclean before God. Mark then adds an explanatory comment that draws out the implication of Jesus’ teaching: all foods are clean. The discussion began with ritual handwashing, but Jesus’ teaching reaches beyond that custom. His reasoning goes further than the Pharisaic tradition and carries wider implications for food-based purity concerns.

Then Jesus states the heart of the matter plainly. What defiles a person comes from within, from the human heart. Here, “heart” does not mean mere feelings. It refers to the inner moral center of the person. From there come evil thoughts and acts: sexual immorality, theft, murder, adultery, greed, evil, deceit, debauchery, envy, slander, pride, and folly. These are the things that truly defile.

Jesus is not saying that outward behavior is unimportant. In fact, the sins He lists are concrete actions and attitudes that reveal what is in the heart. His point is that external controls cannot solve the deeper problem. Ritual management cannot cleanse a corrupt inner life. Real uncleanness is moral and inward, and it shows itself in sinful words, desires, and deeds.

This passage, then, gives both a warning and a correction. It warns that religious language and visible devotion can hide a heart that is far from God. And it corrects the false idea that holiness can be secured mainly by external rules while the inner person remains unchanged. God’s command must govern His people, and the true source of defilement must be dealt with at the level of the heart.