- Machlokes if עור משהופשט requires כיבוס
In a Mishnah on the previous Daf, Rebbe Yehudah said that if חטאת blood spattered onto animal hide משהופשט – after it was skinned, it requires כיבוס, but Rebbe Elazar disagrees. In a Baraisa, Rebbe Yehudah darshens to include anything similar to בגד – a garment, which is ראוי לקבל טומאה – “fit” to contract tumah (i.e., even if it is not currently susceptible to tumah, it will be if he decides to use it as is). Therefore, skinned עור must be laundered, since it can contract tumah if the owner decides to use it as is. Rebbe Elazar darshens that it must be like a בגד which is currently susceptible to tumah, whereas skinned עור is not. Three examples are given of garments which have the potential to be מקבל tumah: (1) a cloth smaller than three fingerbreadths square, דאי בעי חשיב עליה – for if he wants, he can decide to use it now as a patch. (2) A garment one decided to embroider, which would be מקבל tumah if he changes his mind. (3) עובצא – a spread intended for eating and sleeping which he decided to trim, would be מקבל tumah if he changes his mind.
- Laundering leather re: חטאת blood and Shabbos
The Mishnah taught that עור is subject to the law of כיבוס, indicating that leather is a launderable material. However, a Mishnah teaches that although filth may only be wiped off from a cloth pillow on Shabbos (without water, which otherwise would constitute laundering), but if the pillow was leather, he may pour water on it until it disappears. This proves that leather is not subject to laundering!? Rav Pappa explains that this reflects a machlokes Tannaim in a Baraisa, where the Rabbonon say חטאת blood is scraped off of leather, while “אחרים” say it must be laundered. Rava objects that a passuk discusses laundering צרעת from leather and therefore concludes that our Mishnah discusses רכין – soft [leathers] which can be laundered, and the machlokes refers to hard leathers (he later explains that the passuk can include hard leathers, because the צרעת softens it). However, since the above Mishnah permitted pouring water on leather pillows, Rava adds: כל כיבוס דלית ליה כיסכוס לא שמיה כיבוס – any laundering which does not include rubbing is not considered laundering. That which Rebbe Chiya bar Abba said, זימנין סגיאין הוה קאימנא קמיה דרב – “Many times, I would stand before Rav, ושכשיכי ליה מסאניה במיא – and I would rinse his shoes with water on Shabbos,” implying that rubbing was not permitted, was either about soft leathers and follows all opinions, or about hard leather and follows the opinion of "אחרים".
- שרייתו זהו כיבוסו
Rava said that any כיבוס without כיסכוס – rubbing is not considered כיבוס. The Gemara asks: אי הכי בגד נמי – if so, it should also be permitted to pour water on a cloth (pillow), yet the Mishnah in Shabbos prohibits it!? It answers: בגד שרייתו זהו כיבוסו – for cloth, its wetting is its laundering, and is prohibited even without rubbing. Rava is following his opinion elsewhere: זרק סודר למים חייב – if one threw a kerchief into water on Shabbos, he is liable (for laundering). He also said: זרק פשתן למים חייב – if one threw flax seeds into water on Shabbos, he is liable. The Gemara explains that this second ruling is not because it is considered planting (since he specified flax seeds and not wheat and barley); rather, because flax seeds emit רירי – secretions which bond them together into a mass, he is liable for לישה – kneading.