Shabbat 59A

הואיל וראוי להקישו על גבי חרס.

It is considered a vessel since a bell without a clapper is suited to strike on earthenware and produce a sound of similar quality to that produced by a clapper. If so, even when the clapper is removed, the bell may still be used for its original purpose.

איתמר נמי, אמר רבי יוסי ברבי חנינא: הואיל וראוי להקישו על גבי חרס. רבי יוחנן אמר: הואיל וראוי לגמע בו מים לתינוק.

It was also stated that R' Yosei, son of R' Ḥanina, said: It is considered a vessel, since a bell without a clapper is suited to strike on earthenware. R' Yoḥanan said: It is considered a vessel, since it is suited for use to give water to a child to drink.

ורבי יוחנן לא בעי מעין מלאכה ראשונה? והתניא: ״וכל כלי אשר ישב עליו וגו׳״⁠ — יכול כפה סאה וישב עליה, כפה תרקב וישב עליה יהא טמא, תלמוד לומר: ״אשר ישב עליו הזב״⁠ — מי שמיוחד לישיבה, יצא זה שאומרים לו: עמוד ונעשה מלאכתנו.

And with regard to the essence of R' Yoḥanan’s statement, the Talmud asks: And does R' Yoḥanan not require that the vessel’s new usage must be of the same type as the original labor in order for it to retain its ritual impurity after it has undergone change? Wasn’t it taught in a baraita: “Every bed on which a zav is lying is ritually impure and every vessel on which he is sitting should be ritually impure” (Leviticus 15:4). I might have thought, based on this verse, that if one overturned a vessel the size of a se’a and sat on it, or overturned a vessel the size of a half-se’a [tarkav] and sat on it, the vessel would become ritually impure. Therefore, the verse states: On which the zav is sitting, i.e., that which is designated for sitting, excluding that vessel with regard to which one says to the zav: Stand and we will perform our labor with the vessel. In that case, because the vessel is primarily used for purposes other than sitting, it does not become ritually impure even when the zav sits on it.