Talmud do Kelim 26:10

There⁴⁷Mishnah Kelim 26:4. The only things that may be impure are living humans, dead humans and animals, vessels and garments, food and drink, and houses. Tractate Kelim deals with the impurity of vessels and textiles. In that tractate, “pure” means that the vessel in question cannot possibly become impure; “impure” means that it may become impure if exposed to impurity.
If a vessel is used as a container, it can become impure as long as it can be used as container. If an impure vessel springs a leak large enough to make it unusable for its primary purpose, it becomes pure. Animal hides used as containers for water or wine are obtained by skinning slaughtered lambs or sheep. The skin then is open at the neck, the tail, and the four feet. If the feet and tail end are sown tight, there is no doubt that a permanent container was formed which may become impure. If the feet are only tied with rope, they also can become untied; the vessel so created is temporary and cannot become impure. The anonymous Tanna states that Arabs never sow their skins; they have developed a technique to tie the skins with rope to create permanent vessels. R. Meïr extends the rule to all skins whose knots are not supposed to be opened. R. Yose notes that any knot can be untied without damaging the skin; hence, no knot is permanent., we have stated: “All tied-up water skins are pure except those of Arabs. Rebbi Meïr says, temporarily tied ones are pure, permanently tied ones are impure. Rebbi Yose says, all tied ones are pure.” Some Tannaïm state it inverted⁴⁸They switch the statements attached to the names of R. Meïr and R. Yose. This invites comparison with the Mishnah here.. Rebbi Jacob bar Aḥa in the name of Rebbi Yasa: Like our Mishnah. Rebbi Yudan said, the indicator of Kelim is Kilaim⁴⁹In Kilaim, a “futile” tree is turned into a prop for the vine and loses its character of tree by the vintner’s intention as stated in the preceding paragraph; so likewise the knots with which the skin is tied are temporary or permanent according to the intention of the owner. If we do not change the names in Kelim, the arguments of R. Meïr become consistent; the Mishnah Kelim should not be changed., for if it were not so, what would be the difference between permanent and temporary tie? In the House of Rebbi Yannai they said: A permanent tie must be cut, a temporary tie does not have to be cut⁵⁰The House of Yannai disagree with R. Yasa: The difference between temporary and permanent knots is not one of intent but of fact. A temporary knot is one that may be untied by hand, even if it is intended to be permanent. A permanent knot is one that cannot be untied with one’s fingers; it is so tight that it can be removed only by cutting the rope. In that case, a tool was needed to create the openings; this action is as if one used a drill to make a hole in a pot, which destroys the vessel and makes it pure. As a consequence, the permanently tied skin is a vessel and can become impure; there are parallel arguments in Kelim and Kilaim..

HALAKHAH: So is the Mishnah: Because it needs the shoe-maker’s form²⁶⁷Blackening a shoe is not really professional work; it can be done by everybody, but it needs professional tools. Babli 15a.. Is the Mishnah Rebbi Eliezer’s? As we have stated there²⁶⁸Mishnah Kelim 26:4., “the shoe on the shoe-maker’s last, Rebbi Eliezer declares pure but the Sages declare impure²⁶⁹In this context, “pure” means “impervious to impurity”, “impure” means “possibly impure”. For R. Eliezer a shoe still on the last is not an implement, therefore it does not fall under any of the categories of things that may become impure. For the Sages, the moment the shoe is fully sewn and may be worn immediately after being removed from the last, it is a shoe and therefore subject to impurity. Babli Šabbat 141b..” It is the opinion of everybody. It is different here since he is like finishing an implement on the holiday²⁷⁰In the case of the Mishnah, while a person may be embarrassed when wearing a shoe with leather in its natural color, the shoe is not less wearable than a regularly dyed one. Therefore blackening the shoe is not really “hitting with a hammer”, the biblically prohibited action on the Sabbath and holidays of turning a work-piece into an implement, but it looks like it and therefore must be rabbinically forbidden.. It was stated²⁷¹Since on the intermediate days one may prepare clothing for immediate use.: One does not dismantle a shoe from the last on the holiday, but one dismantles a shoe from the last on the intermediate days of the holiday²⁷¹Since on the intermediate days one may prepare clothing for immediate use..