Mark 7:13 (AMPC) says 'Thus you are nullifying and making void and of no effect [the authority of] the Word of God through your tradition, which you [in turn] hand on. And many things of this kind you are doing.' The Pharisees and scribes were concerned that Jesus and His disciples were not following the traditions of men. They were promoting outward displays of religious ceremonies that had nothing to do with an inward change of heart. It had everything to do with ritualistic tradition and nothing to do with worship of the living God. I strongly encourage you to read verses 1 - 23 of Mark 7. Jesus really puts everything in place, and even tells them in verse 6 that what Isaiah had written was truth and even called them hypocrites which means pretenders. Isaiah 29:13 (AMPC) says 'And the Lord said, forasmuch as this people draw near Me with their mouth and honor Me with their lips but remove their hearts and minds far from Me, and their fear and reverence for Me are a commandment of men that is learned by repetition [without any thought as to the meanings].' The Pharisees and scribes were speaking of everything being ceremonially cleansed on the outside and that the food and the utensils used for the food must be cleansed before it was eaten. But Jesus spoke to the people and His disciples in verses 15 and 16 of Mark 7 (AMPC) and said 'there is not [even] one thing outside a man which by going into him can pollute and defile him; but the things which come out of a man are what defile him and make him unhallowed and unclean.' Remember when Jesus said in the second part of Matthew 12:34 'For out of the abundance of the heart the mouth speaks.' Jesus was telling His disciples that the food and the things that come into the mouth do not enter the stomach, but rather are expelled as waste, so eating with unwashed hands do not defile the man (Mark 7:18-23) . It's what comes out of his mouth (which proceeds from his heart) that defiles a man. This is just one example of how man's traditions cannot take the place of God's wisdom, nor will it ever. The Word of God is His wisdom, and it is just a small part of it. Drop the traditions of men and worship God in spirit and in truth (John 4:24).