Mishnah Kelim 8:4-5

Sugya Map

• Core Issue: Does the avir (airspace) of an earthenware vessel (kli cheres) impart impurity to other vessels inside it?
• Primary Sources: Mishnah Kelim 8:4-5; Vayikra 11:34; Sifra (Torat Kohanim) ad loc.
• Nafka Mina: Whether a metal pot inside a contaminated oven becomes tamei via the oven’s airspace or only through physical contact with impure contents.

Text Snapshot

• Mishnah Kelim 8:4: "A pot which was placed in an oven, if a sheretz was in the oven, the pot remains clean, since an earthenware vessel does not impart impurity to [other] vessels."
• Nuance: The contrast between okhelin/mashkin (food/liquids) and kelim (vessels). The gezeirat hakatuv limits the avir effect to ingestibles.

Readings

• Rambam (Comm. ad loc.): Employs the Sifra logic: the verse specifies "all that is within it shall be impure from all the food that is eaten." By exclusion, vessels are exempt from avir impurity.
• Rash MiShantz: Highlights that if the pot contains liquid (mashkeh), the liquid absorbs the oven's impurity via avir, and subsequently, the liquid renders the pot tamei via contact (k'din kol mashkin).

Friction

• Kushya: If the avir of the oven is potent enough to contaminate food, why does the vessel itself remain immune? Does the "container" not participate in the oven’s state?
• Terutz: The Torah’s restrictive phrasing (t'la "mi-kol ha-okhel") creates a formal boundary. The vessel is a protective entity; it is not "food." It only succumbs when the mashkeh inside acts as a bridge—a secondary, contact-based transmission (tumat mashkin).

Intertext

• Sifra, Shemini, Perek 7: Explicitly derives okhelin vs. kelim from the verse.
• SA, YD 158: Discusses the transfer of impurity via liquids; the logic of mashkeh acting as a vector remains the standard mechanism for indirect contamination in Tahorot.

Psak / Practice

The halacha maintains a rigid distinction between avir (which only affects ingestibles in cheres) and contact. In meta-halachic terms, this reinforces a "functional" definition of impurity: the oven's avir targets the sustenance inside, not the functional infrastructure (the vessels) itself.

Takeaway

Impurity in Kli Cheres is teleological: it targets the "food" cycle. If the vessel is empty, it is immune to the oven's avir, proving that in Tahorot, the "object" is defined by its contents.