Cross reference
Mark 7:8
8 "For you set aside the commandment of God, and hold tightly to the tradition of men--the washing of pitchers and cups, and you do many other such things."
Mark 7:3-4
3 (For the Pharisees, and all the Jews, don't eat unless they wash their hands and forearms, holding to the tradition of the elders.
4 They don't eat when they come from the marketplace, unless they bathe themselves, and there are many other things, which they have received to hold to: washings of cups, pitchers, bronze vessels, and couches.)
Isaiah 1:12
12 When you come to appear before me, Who has required this at your hand, to trample my courts?