Matthew 15:2
"Why do thy disciples transgress the tradition of the elders? for they wash not their hands when they eat bread."
Cross References (ranked by relevance)
And when they saw some of his disciples eat bread with defiled, that is to say, with unwashen, hands, they found fault.
And when the Pharisee saw it, he marvelled that he had not first washed before dinner.
Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Christ.
Then the Pharisees and scribes asked him, Why walk not thy disciples according to the tradition of the elders, but eat bread with unwashen hands?
Forasmuch as ye know that ye were not redeemed with corruptible things, as silver and gold, from your vain conversation received by tradition from your fathers;