Keilim 15:4-5

Keilim 15:4

Rabbi Meir says that all hangers are susceptible to impurity except for those of a homeowner’s sifter and sieve; the Sages say that all hangers are insusceptible to impurity except for those of a miller’s sifter, a threshing-floor sieve, a sickle and an investigator’s staff because these are useful in performing the utensil’s work. The general principle is that which is designed to be helpful while the utensil is being used is susceptible to impurity and that which is designed only for use as a hanger is insusceptible.

Keilim 15:5

A miller’s winnowing shovel is susceptible to impurity but one used in storehouses is insusceptible. The shovel used in a winepress is susceptible to impurity but one used in a threshing floor is insusceptible. The general principle is that which is designed to contain things is susceptible to impurity but that which is designed only to gather things is insusceptible.