Mishnah Kelim 2:5-6

Sugya Map

• Issue: The susceptibility of earthen vessel covers (kisuyei kli cheres) to ritual impurity (tumah).
• Primary Source: Mishnah Kelim 2:5–6.
• Nafka Mina: Does the functional usage of a lid (e.g., as a colander) override its formal classification as a "cover," thereby rendering it susceptible?

Text Snapshot

• Mishnah 2:5: "The covers of wine jars and oil jars... are not susceptible to impurity. But if he adapted them for use as receptacles, they are susceptible."
• Nuance: The shift from techunah (inherent structure) to tashmish (functional application). If a lid functions as a container (draining vegetables), it loses its din as a "cover" and gains the din of a "vessel."

Readings

• Rash MiShantz (2:5): Argues that covers are inherently pure because the Torah (Leviticus 11:33) specifies tochei (its interior)—a cover lacks a functional interior.
• Tosafot Yom Tov (2:5): Notes the debate regarding the lid of a lafas (pot). If it lacks a hole or pointed top, it is susceptible because it functions as a platform to drain vegetables (roinki). He concludes this is minhag hamakom—the definition of susceptibility hinges on local culinary habits.

Friction

• Kushya: If tumah is an objective status of a kli, how can it be contingent on the accidental action of an individual (using a lid to drain greens)?
• Terutz: The Mishnah establishes that kelim are defined by shem hamishtamesh (the name/purpose of the user). Once a lid is utilized to hold or process food (draining), it is no longer a "cover" but a "vessel," and the Torah’s category of tochei applies to it.

Intertext

• Leviticus 11:33: The source for tochei—the internal capacity of a vessel.
• Bava Kamma 49b: Discusses tzalochit (flasks) and the use of covers, providing the Talmudic backdrop for what constitutes a "vessel" versus "debris/cover."

Psak/Practice

The principle of tashmish over tzurah (form) remains a bedrock heuristic in Hilchot Kelim. If an object, regardless of its original manufacture, is repurposed to facilitate the containment or processing of food, it enters the domain of susceptibility.

Takeaway

Tumah is not merely an ontological category of matter; it is a legal category of function. If you use it as a vessel, the Torah treats it as a vessel.