Matthew 15:17

Οὔπω νοεῖτε ὅτι πᾶν τὸ εἰσπορευόμενον εἰς τὸ στόμα εἰς τὴν κοιλίαν χωρεῖ, καὶ εἰς ἀφεδρῶνα ἐκβάλλεται;

RBT Translation:

The Witness of The Evening like Garments of Menstruation - Isaiah 64:6, Leviticus 15:19

Do you not understand that everything which is entering into the Mouth, is giving way into the Womb, and it is cast out into a menstrual privy?³⁰

Julia Smith Literal 1876 Translation:
Do ye not yet understand, that everything going into the mouth proceeds to the belly, and is cast out in the privy?

LITV Translation:
Do you not yet perceive that everything entering into the mouth goes into the belly, and is thrown out into the waste bowl?

Footnotes

30

Sordes Menstruorum

A "barbarous" word.

"a word of Macedonian origin, which Suidas calls 'barbarous';"

Strongs #G856 Ἄφεδρος (aphedros) The aphedros has a connection to menstrual impurity. It refers to a place or a state associated with menstrual uncleaness, i.e. flow of blood. This term is found in the Septuagint (Greek translation of the Hebrew Bible) where it corresponds to the Hebrew word נדה (niddah, Strongs #5079), which specifically denotes the "abhorrant rejection" associated with menstruation.

"the whole of the righteous ones of ourselves are like garments of menstruation" Isaiah 64:6.

So, while ἀφεδρών (aphedrṓn) refers to a privy or a place of bodily waste, Ἄφεδρος (aphedros) has a direct association with menstrual impurity in ancient Greek literature and in its usage in the Septuagint. Leviticus 15:19