John Gill Commentary Mark 7:20

"And he said, That which proceedeth out of the man, that defileth the man." — Mark 7:20 (ASV)

And he said
Continued to say in his discourse; though this is left but in the Syriac version;

that which cometh out of the man, that defileth the man ;
meaning, not his excrements, which were unclean by the law, (Deuteronomy 23:13) but what comes out of his heart, by his mouth; or is expressed in action, as appears by what follows; (See Gill on Matthew 15:18).