Matthew 15:8
This people honors me with their lips, but their heart is far from me. The Isaiah 29:13 quotation applied to the Pharisees: the lip-service worship that the prophet identified in Israel's generations is the same worship the Pharisees offer. The tradition of handwashing that they enforce publicly while violating the Fifth Commandment through the corban practice is precisely the honoring-with-lips-while-the-heart-is-far pattern.