Bede the Venerable — as excerpted in the Catena Aurea on Mark 7:1-13

“(ubi sup.) For taking the spiritual words of the Prophets in a carnal sense, they observed, by washing the body alone, commandments which concerned the chastening of the heart and deeds, saying Wash you, make you clean; (Isa. 1:16) and again, Be ye clean that bear the vessels of the Lord. (Isa. 52:11) It is therefore a superstitious human tradition, that men who are clean already, should wash oftener because they eat bread, and that they should not eat on leaving the market, without washing. But it is necessary for those who desire to partake of the bread which comes down from heaven, often to cleanse their evil deeds by alms, by tears, and the other fruits of righteousness. It is also necessary for a man to wash thoroughly away the pollutions which he has contracted from the cares of temporal business, by being afterwards intent on good thoughts and works. In vain, however, do the Jews wash their hands, and cleanse themselves after the market, so long as they refuse to be washed in the font of the Saviour; in vain do they observe the washing of their vessels, who neglect to wash away the filthy sins of their bodies and of their hearts. It goes on: Then the Scribes and Pharisees asked him, Why walk not thy disciples after the tradition of the elders, but eat bread with common hands?”