Commentary for Avodah Zarah 109:13

The midrash here reads the verse in almost the opposite way as the simple reading. According to the “peshat” God is promising to destroy the world due to its sins. But according to the midrash, the sentence is rhetorical—God clearly is not going to destroy the world. The world is full of idolaters who worship nature and yet nature continues, as do the idolaters. So according to the midrash, God is saying that the world should not be destroyed just because of the fools (idolaters).

Agrippas essentially questions the monotheistic nature of the Torah—how can God be jealous of other gods if other gods don’t exist? Moreover, God’s jealousy seems to reveal the fact that foreign gods are at least our God’s equal. Otherwise, why would God be jealous of them.
Rabban Gamaliel seems to shift the meaning of jealousness to something closer to scorn. When Israel takes another god by worshipping idols, it is akin to a man taking a second and inferior wife. The first wife will be scornful of the second wife because she fails to understand why her husband took this woman, when she, the first wife, was superior. But if the second wife was superior, the first wife would not be scornful. She would understand why her husband took a second wife (I would not try this out at home). If Israel was worshipping truly powerful gods, their God would not be jealous. But they worshipped powerless stone, wood and metal. God’s jealously is the sign of their lack of power.

Zunin’s question is an fascinating one, and based on what we know about the placebo effect, we can understand how this happens. People who believe in non-scientific cures can be healed by merely believing in the curer and in his/her purported medicine. Idolaters go to shrines and come out healed, and yet we know that the idol is just a hunk of wood or stone. We see this quite often in both scientific medical studies and in holistic medicine.
Akiva’s answer is not based on the placebo effect, probably because they did not know of this in those days.
Akiva answers that this is in a sense lucky timing. God does not change his ways just because of people’s foolish behavior. If a person has a disease, there is a time set for that disease to become healed. The very fact that this foolish person went to an idolatrous healer does not mean that God should change the course of the illness. That would be a breach of God’s trustworthiness, just as it would be a breach of the banker’s trustworthiness not to pay back the foolish depositor.

Yohanan, based on the verse from Deuteronomy, characterizes sicknesses as being faithful to their oath. The personified sickness takes an oath to leave the person it has afflicted at the appointed time.

It seems that slaying a human being to an idol does bring rain (don’t try this one at home either).

The whole verse that Rav cites reads as follows, “And lest you lift up your eyes to the heavens, and when you see the sun and the moon and the stars, even all the host of heavens, you are drawn away and worship them, and serve them, which the Lord your God has allotted [ḥalak] to all the nations under the whole heaven.” God has allotted the sun, moon and stars to the nations so that they may worship them. God, according to Rav, allows idolatry to be effective, at least at times, so that idolaters should believe in the efficacy of idolatry, and thereby lose their portion in the world to come.
This is a fascinating argument, one that in a sense acknowledges the efficacy of idolatry, and that it is even sanctioned by God. Idolaters are punished, or to put this in another way, are mistaken in their beliefs, not because they believe in idols that do not work. They are mistaken because they do not see the deeper, underlying cause. They are misled by seeing a correlation that is not a true causation. Ultimately, it looks like the sun is a god, it looks like slaughtering a human being to an idol brings rain, but this is just what we see. It is not the true cause. Confusing the visible cause with the ultimate cause is probably something we should all be wary of.

The Talmud brings the above statement of Rav in line with a statement by Resh Lakish. Resh Lakish says that Heaven (God, or some other power, he does not say) helps a person follow the path they have chosen. If they have chosen the dark side, the side of idolatry, then they are provided with help to continue down that path. In the case above, God created the heavenly bodies to give people the illusion that they are gods. But the converse is also true—if people choose the Force, the side of good, they too are aided on their path. So choose wisely.

A Jew may buy a winepress and all of the grapes that are being trodden in it from a non-Jew, even though the non-Jew has lifted up the trodden grapes and moved them into a different heap. At this point in their processing the grapes are not yet considered wine, and therefore their being handled by a non-Jew does not make them “yen nesek”, which is forbidden to Jews. In other words, while we might suspect that non-Jews offer up libations with wine, they will not do so with grapes that are not yet fully pressed, nor will they do so with grape juice. Only when the juice has descended into the vat where it will ferment into wine is it considered yen nesek.
When the wine does descend from the winepress into the vat, the wine which is in the vat is prohibited. However, that which remains above in the winepress is still permitted, even though it has been handled by a non-Jew.

A Jew is allowed to tread grapes in a winepress with a non-Jew, since the wine does not become yen nesekh until it goes down into the vat. However, a Jew may not pick grapes with the non-Jew for the non-Jew causes the grapes to become impure. When the non-Jew puts the grapes in his impure winepress, the grapes will become impure. If a Jew helps him to do so, the Jew is helping to make produce grown in the land of Israel impure. The reason that treading on the grapes is permitted is that as soon as the non-Jew touches them, they are already impure.