The gospel reading recounts an incident of conflict over ritual cleansing between Jesus and some of his opponents. Hand washing probably originated as a regulation observed by the priests when they were offering sacrifice. General hand washing was not mandated by the law itself, but was a custom included in the oral law, ‘the tradition of the elders’. This public criticism was an attempt to shame Jesus so that he would be minimised before others and, having lost his reputation, would cease being a threat to those who opposed him. Jesus’ rebuttal is swift and incisive. He explicitly draws a comparison between those whom Isaiah condemns and the scribes and Pharisees who condemn the disciples. Uncleanness or impurity are not determined by anything external. Defilement originates from the innermost recesses of the heart.