For the Pharisees and all the Jews do not eat bread unless they have washed their hands well, because they keep the tradition of the elders.
Here the Evangelist explains the historical and cultural basis of the issue. It was not about a direct commandment of the Mosaic law, but about the “tradition of the elders.” That is, these customs had been formed later and were gradually elevated so much that for many they became almost as binding as the law itself. Such traditions could at first be presented as a means that helps discipline, but when a person makes them equal to the word of God or gives them a greater place, spiritual distortion begins. The outward washing could remind one of the importance of purity, but when it becomes one of the main measures of holiness, a person forgets that God looks first of all at the heart. Here we see how, in religious life, secondary matters can be pushed to the front while the most important ones are neglected.