Mark pauses mid-story to explain handwashing to his readers: “the Pharisees, and all the Jews, except they wash their hands oft, eat not” (7:3-4). A Gospel writer translating Jewish practice for outsiders is this layer's own method inside the canon. The washing is netilat yadayim, a ritual pouring over the hands before bread, extending priestly purity to the ordinary table; the Mishnah gives it a whole tractate (Yadayim 1:1), and its schools debated the meal's washings in detail (Berakhot 8:2 records a Hillel-Shammai dispute over the order of washing and mixing the cup). The korban vow Jesus then confronts, property locked away from one's parents by a dedication formula, is explained in this site's note on Numbers 30.

Verse 19's closing phrase, which most translations render “thus he declared all foods clean,” asks for plain honesty at the point of contact: observant Judaism keeps the food laws (kashrut) to this day and does not read the verse as ending them; the Christian church, reading Mark with Acts 10 and 15, historically has. The entry states the difference as difference. What both readings share is the verse's own center: defilement is not conquered at the lips but at the heart, “for from within, out of the heart of men, proceed evil thoughts.”