Eruvin 79A

לא ביטלו ⁠— לא. אמר רב הונא: מאן תנא אהלות ⁠— רבי יוסי היא.

However, if he did not nullify it, no, the house retains the status of a house, although it is filled with hay. Rav Huna said: Who is the tanna who taught tractate Oholot? It is R' Yosei, and the tanna of the Mishnah does not accept his opinion.

אי רבי יוסי איפכא שמעינן ליה. דתניא, רבי יוסי אומר: תבן ואין עתיד לפנותו ⁠— הרי הוא כסתם עפר, ובטל. עפר ועתיד לפנותו ⁠— הרי הוא כסתם תבן, ולא בטיל.

The Talmud asks: If that Mishnah is in accordance with the opinion of R' Yosei, there is a difficulty, since we heard him say the opposite, as it was taught in the Tosefta that R' Yosei says: In a case where there is a house full of hay and the owner does not intend to remove, it is considered as though it were filled with indeterminate dirt, and it is therefore nullified. However, if the house was full of dirt that he intends to remove, it is considered as though it were filled with indeterminate hay, and it is therefore not nullified. Apparently, the decisive factor for R' Yosei is not the specific material in the house, but whether or not the owner intends to remove it.

אלא אמר רב אסי: מאן תנא עירובין ⁠— רבי יוסי היא.

Rather, Rav Asi said: Who is the tanna who taught tractate Eiruvin? It is R' Yosei, who does not accept the opinion of the tanna of tractate Oholot.

רב הונא בריה דרב יהושע אמר: טומאה אשבת קרמית?! הנח איסור שבת, דאפילו ארנקי נמי מבטל איניש.

Rav Huna, son of Rav Yehoshua, said: Are you raising a contradiction between the halakhot of ritual impurity and the halakhot of Shabbat? These two areas of halakha cannot be compared. Leave aside the prohibition of Shabbat. With regard to Shabbat, a person nullifies even a pouch full of money. The pouch may not be moved on Shabbat and is therefore considered fixed in place. However, hay, which may be moved even on Shabbat, is not considered to be fixed in the ditch. With regard to ritual impurity, by contrast, the nullification must be permanent.