Bava Metzia, Chapter 7, Mishnah 7. We continue to discuss the right of workers to eat from the food they are working with. The Mishnah before us presents two cases: the first deals with food that is forbidden to be eaten due to another halachic law, and the second deals with workers performing labor on food that has already reached the completion of its processing.
The First Case - Neta Revai:
The example the Mishnah takes is neta revai, the fruits of the fourth year. Let us assume the workers are harvesting grapes that are in their fourth year. For the first three years, the grapes are completely forbidden to eat due to the law of orlah; in the fourth year, it is permissible to harvest them, eat them, or make wine out of them, but there is an obligation to bring them up to Jerusalem and eat them there, similar to the law of maaser sheni. Therefore, as long as the fruits have not been brought up to Jerusalem, or alternatively redeemed onto coins that will be brought up to Jerusalem, they are forbidden to be eaten.
Hence the question: workers who come to work with the expectation of eating from the grapes during the harvest, and the homeowner informs them that the grapes are forbidden to eat because they are neta revai - are they allowed to eat from them? After all, the Torah permitted a worker to eat from the food he is working with. And if the halachah is that they are forbidden to eat, they would have a claim of a mistaken transaction: they were hired under false pretenses, as they can claim that had they known in advance that they could not eat from the grapes, they would have taken another job in a place where they would have the right to eat.
"Hasochar es hapoalim laasos beneta revai shelo" - A homeowner hires day laborers to work in his vineyards that are in their fourth year, whose grapes are forbidden to eat.
"Harei elu lo yochelu" - This is the first stage: the workers are not allowed to eat from the grapes, even though the Torah permitted a worker to eat from the food he is working with, since these grapes are inherently forbidden to eat.
"Im lo hodian, podeh umaachilan" - If the homeowner did not inform them in advance that they would be working with neta revai grapes and would not be able to eat from them, they have a claim of a mistaken transaction, and therefore he must redeem at least some of the grapes and provide them for them to eat.
The meaning of the redemption: the homeowner transfers the sanctity of those grapes that he redeems onto his own coin, adds a fifth to its value, and the coins will be taken to Jerusalem to buy food. The grapes themselves become chullin (non-sacred), and the workers are allowed to eat from them in the vineyard during their work.
The Second Case - After the Completion of Processing:
The second case is similar, but slightly different. As we learned at the beginning of the chapter, there is a window of time during which workers are permitted to eat from the food they are working with, and it has three stages:
Stage 1 - Before the fruit is picked from the tree: they are forbidden to eat from it.
Stage 2 - From the time the ripe fruit is picked from the vine or the tree: they are permitted to eat from it while they are performing labor on it. This stage lasts until the completion of processing, meaning until the food is ready for storage or sale.
Stage 3 - After the completion of processing: workers are once again forbidden to eat from the food they are working with.
The question the Mishnah comes to answer is: what is the law regarding food that has already been packed and moved from Stage 2 to Stage 3? It is already after its completion of processing, the obligation to separate Terumah and maaser (tithes) has taken effect on it, and the workers dealing with it are not allowed to eat from it. What will the law be if something went wrong and it needs to be repacked?
For example, with pressed blocks of dried figs: their processing is completed at the time they are prepared, and if they subsequently fell apart a bit and must be pressed a second time, those repressing them are not allowed to eat, since the food had already reached its completion of processing the first time around, at which point the obligation for maaser took effect. The opportunity to eat has passed, and the workers have no right to eat from the figs they are repacking.
The same applies to wine that was put into barrels: once the wine is taken from the winepress, put into a barrel, the scum floating on the surface removed, and the barrel sealed - it is ready for sale or storage. This is its completion of processing, and it becomes obligated in tithes. If the seal is opened and the barrels must be resealed, even though the workers are performing the exact same labor that was done yesterday by other workers - yesterday they were permitted to eat, and today they are not allowed to eat or drink from the wine.
"Nisparsu igulav, niftachu chabiyotav" - his cakes of figs that were already pressed broke apart, related to the word for a slice, because they were not pressed sufficiently and must be pressed anew; or his barrels opened and must be sealed anew.
"Harei eilu lo yochelu" - even though the workers are doing the same work that was done yesterday, they are forbidden to eat from the figs while they press them again, or to drink from the wine while they package it again, because the produce has already reached the completion of its processing.
"Im lo hodian - measer uma'achilan" - if the homeowner did not inform them that the food had already reached the completion of its processing the first time and became obligated in tithes, and therefore they are forbidden to eat from it, this is a mistaken transaction. Therefore, he must tithe a certain portion of the wine - and not just the tithes, but all the required Terumah and tithes - and provide it for them to drink while they seal the rest of the barrels.
In summary: In this Mishnah we learned two cases where the workers' right to eat is denied due to another halachic rule: fourth-year produce that has not yet been redeemed, and food that has already reached the completion of its processing and became obligated in tithes, and now requires repeated work. In both cases, if the homeowner did not inform his workers in advance, this is a mistaken transaction, and he must make the food permissible for their consumption - for fourth-year produce by means of redemption, and for food whose processing was completed by means of separating Terumah and tithes.