Keilim 19:10-20:1

Keilim 19:10

Rabbi Meir says that if a manure basket is so damaged that it can no longer hold pomegranates, it remains susceptible to impurity; the Sages declare it is clean because if the basket’s primary function (carrying) is nullified, its secondary function (use as a seat) is also nullified.

Keilim 20:1

If pillows, mattresses, sacks and packing cases were damaged, they remain susceptible to midras impurity. The capacity of a fodder bag to be susceptible is four kav (in the vicinity of two gallons); a shepherd’s bag – five kav; a leather bag – a seah (i.e., six kav); a water skin – seven kav. Rabbi Yehuda says that a spice bag and a traveler’s bag that can hold any amount are also susceptible to midras impurity. If any of these loses a piece, it is rendered clean because if its primary function (as a container) is nullified, its secondary function (use as a seat) is also nullified.