Kelim, Chapter Twenty-Six, Mishnah Four
1) A sandal, one of whose holes was broken but was then fixed, retains its midras uncleanness.
a) If a second hole was broken and it was fixed, it is free from midras uncleanness but is unclean from contact with midras.
b) If the second hole was broken before the first could be mended, it is clean.
2) If its heel was torn off, or if its toe-piece was removed, or if it was torn in two, it becomes clean.
3) A heel-less slipper that was torn anywhere becomes clean.
4) A shoe that was damaged becomes clean if it cannot contain the greater part of the foot.
5) A shoe that is still on the last:
a) Rabbi Eliezer says: it is insusceptible to uncleanness,
b) But the sages say that it is susceptible.
6) All water skins whose holes have been tied up are insusceptible to uncleanness, except for Arabian ones.
a) Rabbi Meir says: if they are tied up for a while, they are clean; but if they are tied with a permanent knot they are unclean.
b) Rabbi Yose says: all tied up water skins are clean.
Section one: The sandal has two holes through which straps are put in to tie the sandal to the shoe. The mishnah deals with the purity of the sandal when one or both of these holes are broken.
This type of mishnah, one which distinguishes between something that has midras uncleanness and something that had contact with midras uncleanness can be found in 18:6-7. My explanation here is similar to my explanation there.
If one hole was broken, and then it was fixed, the whole sandal and even the part with the new hole, retain the midras uncleanness that was there in the original sandal. This is because the new hole is part of the old sandal and the old sandal never lost its impurity.
However, if the second hole broke and then he repaired it as well, the sandal lost its original midras impurity because it is considered new.
Although the original midras impurity is gone, the sandal does have a lesser degree of impurity because it was in contact with something that had midras impurity. When the first hole was repaired it contacted impurity from the rest of the sandal. And even when the second hole broke, and the sandal lost the impurity it had, it did not lose the impurity it had by being in contact with other impure parts of the sandal. This is because the bed continued to be usable.
If both holes were broken at the same time, then the sandal is completely pure, even from contact with midras. This is because when both holes are broken, the sandal cannot be used.
Section two: In these cases the sandal is unusable and therefore it is pure.
Section three: The heel-less slipper has a forefoot but no heel (duh!). Since it is so insubstantial, any missing part renders it is unusable and pure.
Section four: If any shoe is damaged so much that it doesn’t hold even the greater part of the foot, meaning at least half of the foot, it is pure.
Section five: According to Rabbi Eliezer, the shoe’s manufacturing is not considered to be complete until it is removed from the last, the model upon which the shoe is formed. The sages disagree and rule that as long as the work on the shoe has been completed, it is susceptible to impurity.
Section six: The mishnah now begins to deal with water skins. If they have simply been tied up but not sewn shut, they are not fully usable and therefore are pure. They need to be sewn in order to hold in water well. The one exception is the Arabian water skin which was customarily tied tightly and not sewn.
Rabbi Meir says that if the tie is temporary, meant to last only a short time, the skin is not considered a vessel and is pure. But if it is tied with a permanent tie, then it is a vessel and is susceptible.
Rabbi Yose disagrees with both previous opinions. All water skins that are tied up are pure, even Arabian ones, and even ones that are permanently tied. A water skin needs to be sewn in order to be considered a vessel.