MISHNA: These following items are themselves forbidden, and any amount of them renders other items with which they become mixed forbidden: Wine used for a libation; and objects of idol worship; and hides with a tear opposite the heart, indicating the idolatrous practice of sacrificing hearts of live animals.

And this halakha also applies to an ox that has been condemned to be stoned (see Exodus 21:28), from which it is prohibited to derive benefit even before its sentence is carried out; and it applies to a heifer whose neck is broken when a person is found killed in an area between two cities and the murderer is unknown (see Deuteronomy 21:1–9), which is likewise forbidden from the time it is taken down to the river to be killed. In these cases, if the animal becomes mixed in a herd of similar animals, all of the animals in the herd are forbidden.

And this halakha also applies to birds designated for the purification of a leper (Leviticus 14:1–6), and the shorn hair of a nazirite (Numbers 6:18), and a firstborn donkey (Exodus 13:13), and meat that was cooked in milk (Exodus 23:19), and the scape-goat of Yom Kippur (Leviticus 16:7–10), and the meat of a non-sacred animal that was slaughtered in the Temple courtyard. All of these are forbidden themselves, and any amount of them renders a mixture forbidden.

GEMARA: According to what criterion does the tanna who teaches this mishna reckon cases? If he reckons based on any item that is counted, i.e., any item that is significant enough to be considered individually, which therefore cannot be nullified in a mixture even in a very large majority of permitted items, let him also teach the case of significant cuts of an unslaughtered animal carcass. And if he reckons based on items from which deriving benefit is prohibited, let him also teach the case of leavened bread on Passover. Rabbi Ḥiyya bar Abba said, and some say it was Rabbi Yitzḥak Nappaḥa who said: This tanna has two criteria. He reckons based on any item that is both counted and from which deriving benefit is prohibited.

The Gemara challenges: But let the tanna teach the cases of perekh nuts, a type of nut that has a brittle shell, and Badan pomegranates, pomegranates from Badan; as these fruits are considered significant, and when they grow during the first three years after the tree was planted [orla], they belong to the category of items that are counted and from which deriving benefit is prohibited.

The Gemara responds: The Mishna taught that case there, in tractate Orla (3:7), where perekh nuts and Badan pomegranates are listed among the forbidden items that cannot be nullified in a mixture, and it is stated with regard to such items: Those items to which the prohibition of orla applies render the entire mixture forbidden by imparting to it the status of orla, while those to which the prohibition of diverse kinds planted in a vineyard applies render the mixture forbidden by imparting to it the status of diverse kinds planted in a vineyard. Therefore, it is unnecessary to mention those cases here.

The Gemara suggests: But let the tanna teach the case of loaves of a homeowner, each of which is unique and significant, with regard to the prohibition against deriving benefit from leavened bread on Passover. The Gemara explains: Whom did you hear who says that such loaves are not nullified in a mixture? This is taught by Rabbi Akiva, and he taught it there in tractate Orla (3:7): Rabbi Akiva adds to the list the loaves of a homeowner.

At the end of the mishna here, the tanna reiterates the halakha stated at its beginning, saying: All of these are forbidden themselves, and any amount of them renders a mixture forbidden. The Gemara asks: The purpose of this reiteration is to exclude what? The Gemara answers: It serves to exclude any item that is counted but from which deriving benefit is not prohibited, or to exclude items from which deriving benefit is prohibited but that are not counted.

MISHNA: In the case of wine used for a libation that fell into a wine cistern, it is prohibited to derive benefit from all of the wine in the cistern, even if the volume of the wine used for a libation was tiny in comparison to the volume of the wine in the cistern. Rabban Shimon ben Gamliel says: All of the wine in the cistern may be sold to a gentile, and the money paid for it is permitted except for the value of the wine used for a libation that is included in it.

GEMARA: Rav says: The halakha is in accordance with the opinion of Rabban Shimon ben Gamliel in a case where a barrel of wine used for a libation became intermingled with barrels of permitted wine, but not when the wine itself became mixed with permitted wine. And Shmuel says: Even when the wine itself became mixed with permitted wine, the halakha is in accordance with the opinion of Rabban Shimon ben Gamliel. And likewise, Rabba bar bar Ḥana says that Rabbi Yoḥanan says: Even when wine became mixed with wine, the halakha is in accordance with the opinion of Rabban Shimon ben Gamliel. And likewise, Rabbi Shmuel bar Naḥmani says that Rabbi Ḥanina says: Even when wine became mixed with wine, the halakha is in accordance with the opinion of Rabban Shimon ben Gamliel. And likewise, Rav Naḥman says that Rabba bar Avuh says: Even when wine became mixed with wine, the halakha is in accordance with the opinion of Rabban Shimon ben Gamliel.

Rav Naḥman says: The practical halakha is that with regard to wine that was actually used for a libation, wine that became mixed with wine renders the entire mixture forbidden, but if a barrel became intermingled with barrels of permitted wine, it is permitted to sell the barrels in the manner described by Rabban Shimon ben Gamliel. With regard to nondescript wine of gentiles, which is forbidden due to the suspicion that it was used for a libation, even if wine became mixed with wine, it is permitted to sell the mixture in the manner described by Rabban Shimon ben Gamliel.