Commentary for Avodah Zarah 147:13

1) If one cask of yen nesekh is mixed up with even one thousand kosher casks, they are all forbidden.
2) If one statue used for idolatrous purposes is mixed up with even one thousand statues that were not used in idolatry, they are all forbidden.
3) In chapter two we learned that idolaters would make circular holes and take out the animals heart and use it in worship. If a piece of one of these skins is mixed up with a large quantity of regular animal skins, they are all forbidden.
4) An ox that killed a man is to be sentenced to death (Ex. 21:28). If this ox becomes mixed up with other oxen, they are all forbidden. Note that in all of the cases of live animals in this mishnah, the same rule is true if the meat of the animal is mixed up with the meat of other animals.
5) This heifer is the one referred to in Deut. 21:4. It is used to expiate the blood guilty for a murder where the murderer has not been caught. If this heifer, after it has been designated to be part of the ritual and is on its way down to the wadi where its neck will be broken, should become mixed up with other heifers, they are all prohibited.
6) When a leper becomes cleansed of his disease, he must bring two birds as a sacrifice (Lev. 14:4). If they are mixed up with other birds, they are all forbidden. 7) When a nazirite ends his term of naziriteship, he must shave (Num. 6:18). Should his hair, once it is shaved off, become mixed up with other hair, it is all forbidden. In other words, no nazirite hair wigs!
8) The first born of a donkey is usually redeemed by giving a sheep to the priest in place of the donkey (Ex. 13:13). If this newborn donkey should become mixed up with other donkeys before it is redeemed, they are all forbidden.
9) If a piece of meat, cooked in milk should become mixed up with other kosher pieces of meat, they are all forbidden.
10) The scapegoat is the goat sent to Azazel on Yom Kippur (Lev. 16:22). If it should become mixed up with other goats, they are all forbidden.
11) It is forbidden to slaughter non-sanctified animals in the Temple court. If the carcass of an animal slaughtered in this fashion should become mixed up with other carcasses, they are all forbidden.

R. Hiyya b. Abba clarifies that to be on the list in the mishnah, the substance needs to be something customarily sold by number, therefore it does not included hametz, which is sold by weight or volume. It also needs to be something which may not be put to any use, and therefore the list does not include meat not properly slaughtered, which may be used and just not eaten. However, the halakhah in the mishnah is true with regard to these substances, even though they are not listed.

These nuts and pomegranates also could have been on this list, but the tanna taught them already in Mishnah Orlah 3:7. The nuts and pomegranates are listed there explicitly.

Loaves made by a householder that are leaven are also an item that could have been in this list. But again, it is found in Orlah 3:7 where it is properly attributed to R. Akiva.

The Talmud reads the last clause as excluding any item that is not both customarily sold by number and prohibited from all use. This is in line with the explanation above.

This mishnah contains a dispute between Rabban Shimon ben Gamaliel and the anonymous mishnah with regards to the prohibition of a mixture of yen nesekh and permitted wine. According to the first section in the mishnah it is forbidden to derive any benefit from even a mixture of yen nesekh and other wine. In essence, the wine must be thrown away. According to Rabban Shimon ben Gamaliel, the Jew may remove a quantity of wine from the mixture that corresponds to the quantity of yen nesekh which fell in, and the rest he may sell to a non- Jew. In this way he is not deriving any financial benefit from yen nesekh.

According to Rav, the halakhah follows R. Shimon b. Gamaliel’s more lenient opinion only when casks of yayin nesekh get mixed up. But if wine falls into other wine, it is all strictly prohibited. But all other amoraim (and the list is quite long) hold that the halakhah follows R. Shimon b. Gamaliel in all cases—the wine may always be sold except for the amount of yayin nesekh that fell in.

R. Nahman distinguishes between yayin nesekh, wine which we know was libated, and ordinary wine belonging to gentiles. With the former, the halakhah follows R. Shimon b. Gamaliel only when casks are mixed up. But when it comes to ordinary wine, the rule is always lenient. The mixture may be sold minus whatever amount of yayin nesekh was part of the mixture.