Matthew 15:2-3

15:2 “Why do your disciples disobey the tradition of the elders? For they don’t wash their hands when they eat.” 15:3 He answered them, “And why do you disobey the commandment of God because of your tradition?

Mark 7:2-5

7:2 And they saw that some of Jesus’ disciples ate their bread with unclean hands, that is, unwashed. 7:3 (For the Pharisees and all the Jews do not eat unless they perform a ritual washing, holding fast to the tradition of the elders. 7:4 And when they come from the marketplace, they do not eat unless they wash. They hold fast to many other traditions: the washing of cups, pots, kettles, and dining couches.) 7:5 The Pharisees and the experts in the law asked him, “Why do your disciples not live according to the tradition of the elders, but eat with unwashed hands?”

John 3:25

3:25 Now a dispute came about between some of John’s disciples and a certain Jew concerning ceremonial washing.