Shabbat 49B

אבא ⁠— שלחא הוה, ואמר הביאו שלחין ונשב עליהן.

My father was a tanner, and one Shabbat he said: Bring me hides and we will sit on them (Rabbeinu Ḥananel). In other words, even the hides of a craftsman may be moved on Shabbat.

מיתיבי: נסרין של בעל הבית מטלטלין אותן, ושל אומן אין מטלטלין אותן. ואם חישב לתת עליהן פת לאורחין ⁠— בין כך ובין כך מטלטלין! שאני נסרים דקפיד עלייהו.

The Talmud raises an objection from a baraita: With regard to wooden boards belonging to a homeowner, one may move them on Shabbat; however, those belonging to a craftsman, one may not move them. And if, however, he thought to place bread upon them for guests, both these, the boards of the homeowner, and those, the boards of the craftsman, may be moved. Apparently, the raw materials of a craftsman may not be moved on Shabbat. The Talmud answers: Wooden boards are different in that one is particular about them that they not be damaged. Hides, on the other hand, are not damaged when one sits on them.

תא שמע: עורות, בין עבודין ובין שאין עבודין, מותר לטלטלן בשבת. לא אמרו עבודין אלא לענין טומאה בלבד. מאי לאו לא שנא של בעל הבית, ולא שנא של אומן? לא, של בעל הבית.

The Talmud cites another proof. Come and hear that which was taught in a different baraita: With regard to hides, whether they are tanned or whether they are not tanned, it is permitted to move them on Shabbat. The rabbis said that tanned hides have a unique legal status, distinct from the status of hides that have not been tanned only with regard to ritual impurity. Only tanned hides become ritually impure. What, is it not saying that there is no difference whether they are hides belonging to a homeowner and there is no difference whether they are hides belonging to a craftsman; in both cases they may be moved on Shabbat? The Talmud rejects this argument: No, the baraita is referring exclusively to hides belonging to a homeowner.