Matthew 15:20
These are the things which defile the man;
but to eat with unwashed hands does not defile the man.
The Law of the Lord had no precept that dealt with washing hands before eating. This washing of the hands before meals was a precept devised and instituted by ancient lawyers. This human precept had not been observed by the disciples.
This was criticized on the part of the scribes and Pharisees. However, the Savior declares that eating with unwashed hands does not defile. Man is, however, defiled by that which proceeds from his evil, corrupt heart.
That which proceeds out of the mouth is a product of the corrupt heart. The impurity within makes unfit for fellowship with God. Sinful deeds and words spring from a sinful heart. The leaders of the people paid no attention to that.
Also among us there is a danger of human ordinances that cannot be found in the Law of God. The Lord open an eye to the uncleanness of the heart, and make supplication for cleansing.