Avodah Zarah 059

5:
The last two clauses of our present mishnah are not concerned with non-Jews but with Jews. They are concerned with Jews who work in the food industry of Eretz-Israel but are not meticulous about the rules and regulations concerning ritual purity. Such people are wreaking havoc with the ritual purity of the priestly and levitical dues.

6:
We have explained these dues on many occasions: here is a very brief recapitulation:

Every agriculturalist in Eretz Israel had to set aside certain 'taxes' from his produce. The first was Terumah. Terumah was to be given to any Kohen [priest] the farmer chose.

1. The main terumah (Terumah Gedolah) consisted of an amount of produce that was left to the farmer to determine. According to strict Torah law any amount of the produce was sufficient ('even a single ear of wheat'). However, rabbinic enactment gave the farmer three actual options: one fortieth of his produce (for the generously-minded), one fiftieth (for the average person) or one-sixtieth (for the tight-fisted).
2. Terumat Ma'aser (Terumah from the Tithe) consisted of 10% of the tithe that had been given to a Levite; this donative the Levite had to set aside to give to a Kohen (any Kohen).
3. Apart from the Terumah (which amounted to something between 1.7% and 2.5% of his yield) the farmer had to give Ma'aser, a tithe of 10%, to the Levite of his choice (from which, as we have already mentioned, the Levite had to give a priest a 10% cut).
4. After the farmer had separated off the terumah and the (first) ma'aser, he had to deduct a further 10% from what was left. This (second) ma'aser was to be expended in Jerusalem. However, in the third and sixth year of each sabbatical cycle of seven years, instead of being expended in Jerusalem it was given to the poor of the farmer's choice.

7:
The reason why it is forbidden to work (with foodstuffs) with such people is because we are warned not to encourage sinners in their sins. On the contrary, we have a duty to encourage them to keep as far as possible from such wrongdoing. Well known is the motto of the sages in such cases:

The nazirite was a person who had made a vow of abnegation. (The basic details are given in the Torah [Numbers 6:1-6].) In every culture there are people who feel that they must deprive themselves of some of the good things of life: possessions, society, sex and so forth. Medieval monasticism is a good example, where people took vows of 'poverty, chastity and obedience' – in other words, they vowed to deprive themselves of possessions, sex and independence. However, in the provisions of the Torah we find that there are already restrictions 'built in'. The Nazirite may only deprive himself of three things (consumption of alcohol, cutting of hair and contact with a corpse) and that only for a certain period of time. When the time is up the vow is terminated. The dictum of the sages means that just as we warn a nazirite to keep far from the vineyard – lest he be tempted to break his vow of abnegation – so we must be very wary of giving even unwitting support to those who sin.

8:
The Gemara [AZ 58b] explains that the barrels which we are permitted to carry with such a Jew to and from the winepress are empty barrels. In the case of the baker, we are permitted to assist him in transporting his loaves from the bakery to the shop where they will be sold because the damage has already been done: the bread is ritually impure and there is no way that we can make it pure now.

Concerning AZ 056 Avraham Arbiv, writes:

It seemed to me that the discussion in the shiur had not finished. The last sentence ("We would be encouraging…") remains unexplained.

I respond:

My apologies if the explanation was not clear. You will recall that the sages in Rome had an altercation with some non-Jewish clerics. They had asked why Israel's God does not destroy the objects of idolatry if He is so opposed to it. The response was that objects such as the sun, moon and other heavenly bodies are of benefit to mankind. The clerics retort, quite logically, that according to that reasoning God should destroy all objects of heathen veneration that are not of benefit to mankind. The response of the sages is that the result of such selective destruction would be that the heathen would point to the objects that had not been destroyed and say that this – their survival – proves their divinity. I hope this clarifies the argument of the sages.

In the previous shiur we noted that the sages changed their mind concerning when the juice of grapes becomes Yeyn Nesekh. Amnon Ron'el writes:

The explanation about the sages changing their mind sounds very intricate: first they thought as mishnah 9 then they decided according to mishnah 8. Also, the parallel between the non-Jew and the Jew who works while in a state of ritual impurity does not indicate ownership, in my opinion, but working together. I think that the reason why treading grapes together with a non-Jew was permitted while prohibiting the harvesting of grapes or touching the juice in the vat may well derive from the fact that during the treading together it is possible to supervise the actions of the non-Jew, but during the harvesting or in the darkness of the vat it is possible that "something bad" could be secretly introduced or mixed with the fruit or the juice. (Poisoning was a widespread method at that time of changing Roman rulers.)