They were hung up, as we say, on the right way to do things. But that right way was not God's way. It was a man-made rule. Jesus' understanding of the Law itself and of God's purpose led to a radical statement about purity. Whatever is made room for in the heart is what grows there.
Purity is a matter of what comes forth from our hearts.
In our day there seems to be a mindset that sees the Law as more honoured in the breach than in the observance. Even the Law itself can be changed or disposed of if we don't really want to live by it. Nothing much has changed in two thousand years. The only righteousness I really have is that which comes from God by grace. From Richard Fairchild.