You Pharisees clean the outside of the cup and dish, but inside you are full of greed and wickedness. You foolish people! Did not the one who made the outside make the inside also? But now as for what is inside you—be generous to the poor, and everything will be clean for you.
The sinners would have included those who did not pay their tithes (one tenth of their income) to the priests, and those who were negligent about the sabbath rest and about ritual cleanliness. The laws and customs on these matters were so complicated that the uneducated were quite incapable of understanding what was expected of them. Education is those days [Biblical times] was a matter of knowing … the law and all its ramifications. The illiterate and uneducated were inevitably lawless and immoral. The ‘am ha-arez, or uneducated peasants, ‘the rabble who know nothing of the law’ (John 7:49) were regarded by even the most enlightened Pharisees, like Hillel, as incapable of virtue and piety.
Albert Nolan, Jesus Before Christianity: The Gospel of Liberation (1976), p. 23.