John Gill Commentary Matthew 15:20

"these are the things which defile the man; but to eat with unwashen hands defileth not the man." — Matthew 15:20 (ASV)

These are the things which defile a man
These are filthy in themselves, and must pollute all in whom they are; they bring a defilement on the whole man, both body and soul, fasten guilt upon him, and expose him to everlasting punishment:

but to eat with unwashed hands defiles not a man :
should a man neglect to wash his hands before eating a common meal, this need give him no uneasiness; he contracts no filth to his soul by this, nor any guilt to his conscience; nor does he break any law of God; nor is he liable to any penalty for such an omission. This is a trifling matter, and merits no regard;

but the things before mentioned are in their nature evil: they are contrary to the law of God; they are abominable in his sight; they render men loathsome and odious to the divine being; and expose them to shame and ruin; and it is only the blood of Christ can cleanse them from the pollution and guilt of them, and secure them from that punishment they deserve.