What does Matthew 15:6 mean?
Some Pharisees from Jerusalem have accused Jesus of allowing His disciples to break one of their favorite traditions. These man-made rules were so closely followed as to have nearly the weight of divine law. Their point was to attack the validity of Jesus' role as a rabbi, as well as to continue to dismiss His claims to be the Messiah. If Jesus is not adhering to the "correct" interpretation of their laws, then they will not accept His teaching.Jesus ignored this shallow accusation and immediately shot back with a far more serious allegation. These same critics effectively break an actual command of God thanks to obedience to their human tradition. The fifth commandment clearly implies that children ought to honor and care for their parents (Exodus 20:12). Thanks to a combination of tradition and legalism, the Pharisees allowed the people to claim they were obeying that command by declaring that valuable possessions were "devoted to God." This gave the people a loophole to avoid using those resources to take care of their parents.
Christ makes this point with force: they have exempted their people from honoring their fathers. For the sake of tradition, Jesus says, they have made void the actual revealed word of God to Israel. They attack Jesus for ignoring traditions which have nothing to do with God's commands, while enforcing traditions which overturn the actual commands themselves! What follows is an even more heated condemnation from Jesus (Matthew 15:7).