The Sermon on the mount exposed them in detail. The leaders don't have a clue and He silences them. It is amazing that we have to point this out in our day and age. But it is not a new phenomenon. Animals were put into the law as a substitute for men, but they were at the point where animals were more important than humans.
Personal bias can keep someone from understanding the word.
Again we see the emphasis on the fact that tradition blinded men to the truth. We need to be sure we are not guilty of the same. No day is too holy to do right for God. Jesus' freedom in observing the Sabbath illustrates our freedom in Christ.