פירוש על עבודה זרה 107:4

An altar has more than one stone, whereas a pedestal has only one.
Hezekiah cites a verse that proves that an altar has multiple stones and that in order for it to be annulled it must be completely shattered. The verse refers to how the “iniquity of Jacob” can be expiated.

If a person worships his own animal, it is prohibited. But in general a person does not have the power to prohibit another person’s property, so if he worships someone else’s animal, it remains permitted.

The baraita is raised as a contradiction to the previous baraita. The baraita rules that any animal that was worshipped, even if it was worshipped “under compulsion,” is prohibited. At first the Talmud tries to explain that “under compulsion” refers to one who took his friend’s animal and worshipped it. This would mean it contradicts the first baraita. But Rami b. Hama explains that it simply refers to one forced to worship an animal, not an animal that was stolen and worshipped.

Zera points out that the baraita cannot rule an animal prohibited if it was worshipped under duress. The Torah always exempts one who acts under duress, as we learn in the case of the violated girl. This should extend to the animal as well.
Rava resolves it by noting a progression of verses. Theoretically, idolatry is always prohibited, even under the threat of death. On the other hand, the Torah exempts one who acts under duress. Finally, the Torah also prohibits desecrating God’s name. To resolve all of these seeming contradictions Rava says that one situation refers to something done in private and the other to a public act. In private, a person should worship idolatry rather than die. But in public, at least when it comes to idolatry, a person should be willing to die rather than transgress.
We should note that there is a some blurring here in topic between the status of the animal that was worshipped and the issue of whether a person should allow himself to be killed rather than transgress. Rava seems to be talking about the latter, whereas the sugya is talking about the former. To resolve this we’d have to equate the two. If a person worships idols under duress in private, the animal is not prohibited because the person did not sin. But if the person worships idols in public under duress, just as he should not have transgressed, so too the animal is prohibited.

The rabbis, probably students of Rava, try to find a tannaitic teaching that supports Rava’s view. The pedestals here were worshipped at the time of persecution. This means that they were worshipped under duress. Nevertheless, they are prohibited.
Rava deflects the support (he’s so modest). While most people probably worshipped the idols under duress, it is possible that someone worshipped them willingly. Therefore the baraita is not proof that worship under duress will prohibit an idol.
Ashi goes a step further and says that we can be certain that a Jew willingly worshipped the idol.

Yesterday we saw two baraitot that contradicted each other. According to one baraita, if one worships another person’s animal, the animal is not prohibited. The other baraita hinted that an item worshipped under duress is prohibited.
Hizkiyah solves the contradiction in a different way. The baraita that prohibited the animal referred to a case where the animal was not worshipped but rather the idol was placed on it. Such an act renders the animal prohibited although just bowing down to it does not.

Ada b. Ahava offers another solution to the contradiction. Although in general if one simply worships another person’s property, the property remains permitted, if he actually does something physical, the animal (or other object) can become prohibited.

Nahman believes that R. Huna has already essentially said that while one cannot cause another person’s property to become prohibited, if he performed an idolatrous act on it, something physical, it is prohibited. The situation he describes is one where an animal is lying down before an idol. If the idolater slaughters the animal for the idol, he has rendered it prohibited.

The Talmud asks for Scriptural support for R. Huna’s ruling. If we say that the precedent are priests who are forced to worship idolatry. Such priests may not return to serve in the Temple. The problem is that priests had a choice—they could have chosen martyrdom. But the animal had no choice.

The second possible answer is the altar-stones. When the Greeks defiled the Temple, these stones became prohibited, even though they did not choose to be worshipped. The problem is that R. Papa already pointed out that the Greeks took technical ownership over the stones and therefore they were prohibited. This is not the case of someone prohibiting something that does not belong to them.