“But what comes out

Of the mouth

Proceeds from the heart.

This is what defiles a man.

Out of the heart

Come

Evil thoughts,

Murder,

Adultery,

Fornication,

Theft,

False witness,

And slander.

These are what

Defile a man.

But to eat

With unwashed hands

Does not defile a man.”

τὰ δὲ ἐκπορευόμενα ἐκ τοῦ στόματος ἐκ τῆς καρδίας ἐξέρχεται, κἀκεῖνα κοινοῖ τὸν ἄνθρωπον.

ἐκ γὰρ τῆς καρδίας ἐξέρχονται διαλογισμοὶ πονηροί, φόνοι, μοιχεῖαι, πορνεῖαι, κλοπαί, ψευδομαρτυρίαι, βλασφημίαι.

ταῦτά ἐστιν τὰ κοινοῦντα τὸν ἄνθρωπον· τὸ δὲ ἀνίπτοις χερσὶν φαγεῖν οὐ κοινοῖ τὸν ἄνθρωπον.

There is something similar to this in Mark, chapter 6:20-23.  Jesus indicated that the true defilement was what came out of a person’s mouth, not what went into it.  He clearly explained defilement.  What came out of the mouth (τὰ δὲ ἐκπορευόμενα ἐκ τοῦ στόματος) proceeded from the heart (ἐκ τῆς καρδίας ἐξέρχεται).  That is what defiled a man (κἀκεῖνα κοινοῖ τὸν ἄνθρωπον).  Out of the heart came (ἐκ γὰρ τῆς καρδίας ἐξέρχονται) such things as evil or wicked thoughts, plots or deliberations (διαλογισμοὶ πονηροί), murders or killings (φόνοι), adulteries (μοιχεῖαι), sexual immoralities, fornication or pornography (πορνεῖαι), theft (κλοπαί), false witness or false testimony (ψευδομαρτυρίαι), and slander, abusive language, or blasphemy (βλασφημίαι).  These were the things that defiled a man or person (ταῦτά ἐστιν τὰ κοινοῦντα τὸν ἄνθρωπον).  You can clearly see what Jesus, his disciples, and the early Christian community considered as sins or defilements that made a person unclean.  But to eat with unwashed hands did not defile a man (δὲ ἀνίπτοις χερσὶν φαγεῖν οὐ κοινοῖ τὸν ἄνθρωπον) or make him unclean.  Notice that there is no mention of any unclean foods as in Mark.  Perhaps the Jewish Christians around Matthew still held to Jewish dietary laws.