Moses wrote in the Torah (Deuteronomy 12:32) not to add to his commands, and it seemed to be quite the sport for the Pharisees. When we add laws or traditions they can warp our minds in thinking they came from God.

This is what happened with the Pharisees they saw Jesus breaking the human traditions and believed Jesus was sinning.

Jesus though shows them that they should be more zealous for keeping the integrity of God's law than they are for their human traditions. How many times have people stepped into a church not wearing the Sunday best and people in their hearts jeering at them. They are more zealous for the human tradition of Sunday best than loving their neighbor.

Matthew 15:1-9