The first few verses give us the context. It refers to the Talmudic ritual hand-washing that the Pharisees had made into a binding customary law. It appears to be one of the oldest and most revered customs in Jesus’ time. Hand-washing was not in the Covenant Law. We’ve previously noted how the underlying drift of the Talmud and rabbinical traditions was to hedge about the Law of Moses, as if the Covenant needed protection from the nation, instead of the Covenant protecting the nation. The emphasis was on the Law, making it a deity. This is completely backwards from the ancient Hebrew tradition of understanding Law on a deeper level than the words and ritual provisions. This is another case of legalism, extending mystical rituals into binding nit-picking regulation of mere human behavior.
By Jesus’ time it seems that there had been some resistance to the hand-washing ritual from working peasants, for whom it was quite burdensome to keep the necessary equipment and provisions at hand. It’s no big deal for those whose only work was running their mouths inside nice buildings. This was very much a social status symbol. It was part of the rabbinical standards that one could not be taken seriously without keeping the ritual and teaching it. But Jesus was the rabbi who lived among the rabble and kept most of their habits, to include eating without this prissy ritual washing.
When asked about this, Jesus answered with His own question. It was very pointed: Why do Pharisees use the ancient korban law as an excuse to defy the very heart of the Covenant? Originally korban was a way of designating and setting aside a sacrificial animal or portion of crops for special treatment in preparation for making it an offering in the Temple. It served notice to one’s extended family household take extra precautions and not treat it as just the ordinary product of the family’s agricultural enterprise.
Pharisees found in this a loophole so they didn’t have to share their material wealth with their aging parents. The priests in the Temple began encouraging a special kind of pledged donation trust. Someone would gain all sorts of social religious merit by designating their entire estate for korban, but could still use it while they lived. Thus, the individual Pharisee could then act as if it was a holy duty to protect the value of this “estate in trust” and not give any support to their indigent household elders. This defies one of the Ten Commandments about honoring your parents.
Jesus castigates them using Isaiah’s warning about just this kind of Talmudic nonsense (Isaiah 29:13). Don’t claim to obey the Lord when you’ve piled up customs that pervert the whole purpose of the Covenant. This is a direct attack on the moral character of God, an insult to all of Creation. This is exactly how the Talmud works.
This private conversation took place during a break in Jesus’ routine of teaching the crowds. So Jesus turned to the crowd and said something that pertained to this very issue. It wasn’t the issue of kosher, but specifically the stupid matter of ritual hand-washing. He told them it wasn’t necessary to listen to the Pharisees about that. The Pharisees conflated “dirty” with “ritually impure” — two different concepts in Greek and Hebrew. It’s not what goes in your mouth, but what comes out of it that defiles you.
This infuriated the Pharisees who had come out to investigate Jesus’ ministry. When the disciples mentioned it to Jesus privately, He pointed out that this was a sign that these Pharisees were damned already. This echoes His previous teaching about wheat and tares, but in this case their downfall would come in good time. Evil hearts cannot produce success except in the most artificial contexts. The Pharisees had constructed a society that guaranteed their safety, but sooner or later reality would devour them in their sin.
As they absorbed this, they asked about the meaning of Jesus’ parabolic reference to input and output of mouths. His question back at them was a bit of rebuke, as if they were still too worried over literal meanings instead of testing things with their hearts. So He reminded them of blunt biological facts they already understood. What goes in your mouth is processed and dropped in the chamber pot. What comes out of your life reflects what is in your heart. If your heart is darkened and committed to anything but God, you’ll defile your existence by how you live. He implies that the Pharisees were committed to their own personal comfort, and willing to justify almost any sin through legalism.
If sanitary facilities are convenient, sure, wash your hands before handling food. But don’t let someone load you up with false guilt that misses the whole point of revelation.