Mishnah Kelim 15:4-5

Sugya Map

• Issue: The boundary between keli (vessel) and shammash (accessory/hanger) in the laws of tumah.
• Nafka Mina: Whether an object that facilitates the use of a vessel acquires the vessel’s status, rendering it metamei (susceptible to impurity).
• Primary Sources: Mishnah Kelim 15:4-5, Tosafot Yom Tov ad loc., Rambam, Commentary to Mishnah Kelim 15:4.

Text Snapshot

Mishnah Kelim 15:4: "This is the general rule: [a hanger] that is intended to aid when the instrument is in use is susceptible to impurity and one intended to serve only as a hanger is clean." Leshon nuance: The phrase mesay'in b'sha'at melachah (aiding during work) establishes functional utility as the threshold for keli status.

Readings

• Rambam (Comm. to Mishnah): Defines the mikkel habalashin (detective’s staff) as a tool used to probe straw for hidden grain. He asserts that the hanger is susceptible because the user inserts their hand through it to stabilize the tool during exertion. Chiddush: Intentionality in structural support confers "vessel" status.
• Rash MiShantz: Distinguishes the kavrat garanot (threshing sieve) by noting that workers insert their hands into the hangers specifically when they tire. The hanger becomes a literal extension of the body’s force—chibbur (attachment).

Friction

• Kushya: Why is the hanger of a householder's sieve tahor (clean), while the professional's is tamei? If it’s a functional extension of the tool, the owner's status shouldn't change the object's essence.
• Terutz: The Mishnah hinges on kavana. For a householder, the hanger is merely for storage (teliya). For the professional, the hanger is integral to the ma'aseh (the work itself). The object is redefined by the intensity and mode of its usage.

Intertext

• Mishnah Kelim 12:3: Establishes the principle koll hamchubar l'tamei, tamei—everything attached to an impure object becomes impure. The "hanger" is the legal edge of that attachment.

Psak/Practice

The heuristic for keilim is functional: if an accessory is mesaye'a (active assistance) rather than m'shamer (passive storage), it loses its status as a mere appendage and becomes part of the keli. In modern halacha, this informs the status of peripheral attachments to appliances—if it aids the core function, it shares the appliance's status.

Takeaway

Function defines essence; a hanger is just a hook until the hand requires it for leverage, at which point it becomes a tool.