The concern with outward acts and not the intent of God’s law manifested these particular Pharisees’ blindness to the ultimate source of impurity. Jesus therefore reminded them that the heart is the true source of corruption, not the hands, a truth to which the Torah points (Matt. 15:10–20). We manifest a legalistic heart every time we are critical of others for not observing that which we love even though they are indifferent matters as far as the Bible is concerned.
For further study:
The Bible in a year: