There are two kinds of dirtiness: external and internal dirtiness. The external dirtiness relates to physical hygiene, while the internal one causes harm to the spiritual life. Internal defilement barricades one's relationships with others, and makes oneself unholy before the Divine. External dirtiness is easy to detect because it is noticeable on a person. Internal dirtiness is much harder to recognize, because it is hidden, buried deep in one's heart. A person may seem well presented in appearance, friendly and talkative, but the intention of the heart is uncertain.
The conversation about the defilement began, when the Pharisees, and Sadducees criticized some of Jesus' disciples, who didn't observe the rules, that before consuming any food one must have their hands washed. Jesus took the opportunity to tell the Pharisees, that keeping the spiritual cleanliness was the most important. Impurity of hands would not lead to permanent death, but the impurity of a heart had no eternal life. External cleanliness helped to avoid contracting diseases; internal cleanliness helped to avoid sinning.
After returning from the exile, the Israelites became a new nation, occupied the new land. After years of slavery in Egypt (430 years Ex. 12,40) they seemed to have difficulty in adopting to a new way of life. It was hard to conduct themselves in the free world. The Law reminded the people:
a/ new Feast Days established to commemorate God's saving actions
b/ the Law aimed to bring people closer to God, and
c/ the Law gave instructions to be kind to the orphans, widows and the elderly people.
In responding to a new situation, more rules were given. The new ones were on top of the old ones. Keeping all these laws was a heavy burden for the people. Furthermore, the new laws deviated from the previous ones, and some of them were divorced from the original ones. Jesus wasn't rejecting the traditions, but He accused the Pharisees and Sadducees for failing to keep God's command and offering God only lip- service (Mk 7:6)
The cleanliness of a heart defined the true personality of a person, while the external cleanliness was a societal expectation. For Jesus, lip- service had no depth, the heart was important. What pleased God was not external observation, but the internal cleanliness of a heart. Human regulations were good, only in so far as they reflected the spirit of God's love. When they came to pure human regulations they became heavy burdens for others.
The heart is the place where all our intentions, both good and evil, arise. A heart's desire can either bring a person closer to God, or drive that person to go further away from God. A pure heart brings a person to God, while a corrupt heart pursues one's own way.
Spiritual richness makes a person happy. That person desires no more glory from the outside world, because his/her heart is full of God's love. A person only desires self- praise, and world glory because the heart is empty. His/her spiritual life is poor. People who are spirituality rich care for their spiritual body. People who are spirituality poor neglect their spiritual life. In this sense the rich become richer, and the poor become poorer in spirituality.
We pray to be rich in God's grace.