מסכת כלים

פרק יט משנה י

A mashpeles (a large wicker basket; the type referred to here was used to haul dung or trash, and was made to either go over the back of an animal, with a place for a person to sit, or to be carried by a person, and included a cane-like support for the carrier's weight to allow the person to rest)

that was too damaged to hold pomegranates,

Rabbi Meir rules is tamei (midras)

and the Sages rule is tahor,

as when its main purpose is eliminated,

its secondary purpose is eliminated.

Pillows

and mattresses

sacks (made of sackcloth)

and martzufim (large leather sacks used to transport goods on ships)

that were damaged (and can no longer be used as a container)

are tamei midras (even according the Sages, as sitting was one of the originally intended uses for these items).

The feedbag [that holds at least] four kavs,

the shepherd's pouch [that holds at least] five kavs,

the small leather sack [that holds at least] a se'ah,

the waterskin [that holds at least] seven kavs,

Rabbi Yehuda says

also the spice bag (a very small leather pouch)

and the traveler's bag

of any size,

these are all tamei midras,

and all, if damaged,

are tahor,

as its main purpose is eliminated,

and its secondary purpose is eliminated.