פירוש על עבודה זרה 68:7

All of these items lose their taste of forbidden wine after twelve months and therefore may be used by Jews.

Experts do not put wine into murias. Similarly, they do not mix forbidden fish into brine made of “hilik” which is a permitted fish. Thus one can even eat such murias or such brine.

The murias of an expert is the murias produced from the first and second extracts of the fish. By the third time, there is not much fat left in the fish, and in order to make it taste good, he has to put in wine. That’s why it is prohibited.

R. Aha puts guards around the murias that arrives by ship in Acco to prevent wine being put in there. He does not worry that wine has already been mixed into the murias before it arrives in Acco because in the region from which the wine comes, wine costs four times as much as murias, and therefore no one would mix wine in with it. And we are not worried that the murias might have come from Tyre, where wine is cheap, because shipping it from Tyre was not practical.

The fact that it is prohibited to derive benefit from Bithynian cheese is probably what leads R. Shimon ben Lakish to posit that most of the calves there are used as sacrifices. If the issue was simply non-kosher ingredients, then it should have been prohibited to eat the cheese but permitted to derive benefit from it.

The problem with Resh Lakish’s statement is that even if only a minority of calves were slaughtered for sacrifice, the cheese would still be prohibited, for R. Meir does not follow the majority status. He is also concerned about the minority.
The answer is that if only a minority of calves were slaughtered for idolatry, we would have “two minorities” here. The second “minority” is that the cheese may be made from animals besides calves. Thus only some of the cheese is made from calves, and only a minority of calves are slaughtered for idolatry. If this were true, R. Meir would not prohibit the cheese. Therefore, Resh Lakish had to conclude that a majority of the calves were slaughtered for idolatry.

R. Shimon b. Elyakim points out to Resh Lakish that his statement here seems to contradict a different statement that he made. Elsewhere, R. Yohanan and Resh Lakish argue over whether an animal slaughtered with the intention of using its blood or fat for idolatry is prohibited. Resh Lakish says it is not. So how come here he says that it is.

Resh Lakish here distinguishes between two situations. If one slaughters an animal in order to use its blood or fat for idolatry, the very act of slaughtering does not yet render the animal prohibited. Only inside the Temple would his intention to perform an ancillary act for idolatrous purposes effect the status of the animal. But if he slaughters the animal itself for idolatry, then the animal is prohibited. It was to this case that Resh Lakish referred when explaining the prohibition of Bithynian cheese.

Men did not betroth women with dung of any animals during the Talmudic period, any more than someone would do such a thing now. This is a great example of rabbis using the issue of the viability of betrothal to demonstrate something else. If the dung has value, then the man can perform betrothal with it. The dung of an ox that has been sentenced to be stoned (for murder) evidently has value, despite the fact that one may not derive benefit from the ox. In contrast, the dung of an animal used for idolatry does not have value. Therefore, this act of betrothal is invalid.

The Talmud first attempts to explain this with logic. When it comes to the animals offered as idols, the owner would want them fatter—more food for the gods. Therefore, there dung is something he wanted and it has value. But when it comes to an ox sentenced to be stoned, the owner certainly does not care that they be fattened. Therefore, this dung is unwanted and has no value.

The Talmud first attempts to explain this with logic. When it comes to the animals offered as idols, the owner would want them fatter—more food for the gods. Therefore, there dung is something he wanted and it has value. But when it comes to an ox sentenced to be stoned, the owner certainly does not care that they be fattened. Therefore, this dung is unwanted and has no value.

The second proof is from verses. When it comes to idolatrous objects (things that are proscribed), the word used is “anything.” One may not benefit from anything that comes from idolatry. But when it comes to the ox, the word is “flesh.” One may not derive benefit from its flesh, but one may derive benefit from other parts of the ox.

Rava says that he can prove both of these laws from the mishnah in which R. Joshua and R. Ishmael argue as to why cheese made by non-Jews is prohibited. R. Joshua argued that non-Jews curdle their cheese with rennet made from nevelah (an animal not properly slaughtered). To this R. Yishmael responded that the rennet of a burnt offering is permitted. This proves that non-flesh parts of animals from which one may not derive benefit (like the burnt offering) are permitted. Thus dung from an ox sentenced to be stoned is permitted and can be used for betrothal.