Kelim, Chapter Twenty-Eight, Mishnah Five
This mishnah deals with various cases where one cloth item that is susceptible to impurity is turned into a different item that is also susceptible to impurity. The question is: does it lose its earlier impurity?
1) If a head-wrap that had contracted midras uncleanness was wrapped around a scroll, it is released from midras uncleanness but it remains susceptible to corpse uncleanness.
2) A skin that was made into a rug or a rug that was made into a skin becomes clean.
3) A skin that was made into a [shepherd’s] wallet or a [shepherd’s] wallet that was made into a skin;
a) Or a cushion cover that was made into a sheet or a sheet that was made into a cushion cover;
b) Or a sheet cover that was made into a plain sheet or a plain sheet that was made into a sheet cover, remains unclean.
4) This is the general rule: any object that has been changed into one of the same class remains unclean, but if into one of another class it becomes clean.
Section one: Head-wraps are susceptible to midras impurity for occasionally a person will use it for sitting. However, undecorated scroll covers are susceptible only to corpse uncleanness (see yesterday’s mishnah). So when he changes the head-wrap to a scroll cover it loses its midras uncleanness but it is now susceptible to corpse uncleanness.
Section two: A skin for carrying liquids is not in the same category as a rug. Therefore, if one changes a skin into a rug or vice versa, the vessel is pure. Note that it is susceptible to impurity; it only loses its old impurity.
Section three: In all of these cases he changes something to something else that is in the same general category. Therefore, the object retains its impurity.
Section four: This is the general rule that explains the distinction between the case found in section two and that found in section three.