Commentary for Avodah Zarah 86:21

Abaye explains that the only of God’s attendants that one may not make is the four-faced creatures (human, lion, eagle, ox) of the Divine chariot (see Ezekiel, chapter one). Any other image can be made, including the moon.

Abaye says that only the four-faced angels are prohibited. But earlier we read a mishnah that prohibited the image of a human face.
Judah resolves this by citing a baraita that he at his father’s public lecture. This baraita revocalizes the word “iti,” which means “with me” to read as a direct object “oti.” It is prohibited to draw the image of God, but it is not prohibited to draw any other images, including that of a human.

Abaye (again) answers that the Torah prohibited only the angels that are in the highest order, including those mentioned here. But not, evidently, the moon. Again, Rabban Gamaliel is defended.

This baraita quotes another section of the verse, and used it to prohibit making images of the sun, moon, stars and planets. This seems to refute Rabban Gamaliel.

The Talmud resolves this by stating that this verse prohibits worshipping these heavenly and earthly images. One can make them, but not worship them.

This baraita clearly prohibits making the heavenly images, so again, we have to ask, how could Rabban Gamaliel have made images of the moon.
The Talmud responds with quite a strained answer, one that seems quite certainly to be “making it up.” Rabban Gamaliel did not make the images—someone made them for him. He can use them, because he did not make them.

Introduction
Yesterday’s section concluded by justifying Rabban Gamaliel’s moon images by saying that he did not make them, someone made them for him, so it is okay. Today’s section questions whether it is allowed to use images that someone else made.

People made a seal with the imprint of a face for R. Judah. Shmuel mocked R. Judah and told him to disfigure the seal. This proves that even if others make the image, it is still prohibited.

The ring that they made for R. Judah had a protruding seal, and it is prohibited to wear such a ring. One should not wear such a ring because it looks like an idol. But one can seal with such a ring because the image is sunken in, and therefore does not look so much like an image.
But if the ring’s image is sunken in, then it is permitted to wear it, but one may not sign with it, because such a sign would be protruding. In short, protruding images are prohibited, but sunken ones are not.

The Talmud here cites the fascinating case of a synagogue in Nehardea. The synagogue is called “Shaf Veyativ” which means “destroyed and rebuilt,” and indeed, there does seem to have been a famous destruction of the Jewish community in Nehardea in 247 and then the community was rebuilt. Fascinatingly, there was a statue in this synagogue, certainly something that the rabbis would not have been comfortable with. Rabbis attended this synagogue, but it does not seem that they were leaders of it, nor were they consulted on questions of behavior there. So if Shmuel’s father and Levi attended this synagogue, they must not have been too worried that someone would think they’re worshipping idols.
The Talmud resolves the issue by saying that if many people are around, then we’re not concerned that someone will worship the statue. It seems that the presence of others will act as a deterrent (there are things one might do in private that one will not do in public).

The final problem is again with regard to Rabban Gamaliel—he was an individual, and he had these images in his upper chamber. Why wasn’t he concerned that people would suspect him of worshipping them?
There are three answers:
He was the head of the community, and therefore, other people were always there with him.
The images were in pieces, and it is only prohibited if the image is whole
Rabban Gamaliel had these images for study, and one may make images to study them. This is a very broad relaxation of the prohibition and was frequently invoked throughout history to allow for the making of images.

Rav refers to eating vessels. If the images are covered by the food or liquid in the bowl, then they are “disgraceful,” because one covers the “idol” with food. But if they are above that line, then they are considered respectable, and it is prohibited to make or own them.
But Shmuel thinks that all images on food vessels are “disgraceful,” which is probably an overly strong word here. “Disgraceful” here probably means something closer to “common”—not worshipped. For the image to be “respectable,” i.e. worshipped, it needs to be on some piece of jewelry, items which are accorded a far higher degree of honor.

This baraita accords with Shmuel—to be respectable, the image must be on a piece of jewelry. Otherwise, the image is just a common decoration.

R. Yose uses the case of the golden calf to prove his ruling that one may destroy idols by grinding them up. The other rabbis respond that Moses ground up the calf not in order to destroy it, but because he wanted the Israelites to drink it, the same way that the suspected adulteress has to drink the bitter waters. Idolatry is, according to many of the prophets, similar to adultery, showing lack of faithfulness to one’s god.