Not only was it tradition to wash their hands but to do the dishes. Now for some of us cleanliness is next to Godliness. Nobody wants to eat on dirty dishes or see someone come to the table with dirty hands, so this text was not about dirty dishes or hands, eh. It is more about hearts and minds. The Pharisees wondered why these twelve or so marauders came to the table and began to eat with dirty hands. I imagine over by the wash basin there was a man standing with a towel to dry their hands after washing and along side him there was some sort of tray to collect money. You know what happens when you mess with people’s money. You have trouble.
Jesus flips the script; he attacks their hearts and minds. That is what you have to do sometimes instead of standing by idle. This means sometimes when folk criticize you for something like “dirty hands” they are really talking about something else. That is how I handle rough and unjust criticism. I say in my own mind, "now what is it this person is really saying?" Is it me they have a problem with or is it just a bad day for them. Don’t get me wrong I have learned to love criticism, it is like, art, literary, biblical and historical criticisms. I use them to improve myself and trim my growth edges.
In a nut shell there are some vain folk out here whose only station in life is to make others feel bad. Jesus defends his disciples by attacking their vanity and worship. They have traditions that they follow but their motive is not pure. They (Pharisees) were observing some real free spirits who were no doubt comfortable with Jesus and their new found freedoms. They (disciples) were learning that there was nothing better than dirty hands and a clean heart. A pure heart trumps traditions, dirty hands and dirty dishes every time. Now go wash your hands and your heart.