The agenda no doubt was to criticize Jesus. The Pharisees and scribes noticed that Jesus’s disciples failed to wash their hands before a meal. The Mishna recorded the tradition that this ritual required a minimum amount of water equal to the volume of one and half eggs. This was definitely about ritual and not hygiene! Jesus countered with the legal loophole used by the religious leaders for declaring something dedicated to the temple, and so unavailable to be used for the care of aging parents. They were criticizing about a tradition of the elders; he was convicting them about the Law of Moses. (See Matthew 15:1-20.)
Following this exchange, Jesus addressed the crowds with a proverb: “it is not what goes into the mouth that defiles a person, but what comes out of the mouth; this defiles a person” (Matthew 15:11 ESV). This led his disciples to note the Pharisees were offended by Jesus and to request further explanation of the proverb. Jesus’s reply stressed holiness is developed from the inside out. His reply gives us a glimpse into the habits of holiness.
Be careful with God’s revelation. Jesus noted that the Pharisees were blind guides. If the blind lead the blind, both will fall into the pit. God will uproot what he has not planted. In pursuing holiness and a relationship with God, truth matters.
Be careful what you say. What comes out of our mouths in Jesus’s proverb must refer to what we say. What we say reflects what we are thinking. What we say foreshadows what we will do. The connection between deeds and words is found in Paul’s discussion of sexual immorality and covetousness (Ephesians 5:3-5). Right in the middle of these two themes, Paul warns about the wrong use of words. Some kinds of talk defile. Some kinds of talk sanctify.
Be careful what you think. In Jesus’s explanation of his proverb, he goes further and warns about evil thoughts. Paul also reminds us to think about good and honorable things (Philippians 4:8). Some kinds of thoughts defile. Some kind of thoughts sanctify and make holy.
Although the good news may intervene and change our habits and destiny, God still uses our habits to develop holiness. Someone has wisely said:
Watch your thoughts; they become words.
Watch your words; they become actions.
Watch your actions; they become habits.
Watch your habits; they become character.
Watch your character; it becomes your destiny.