Demai, Chapter 7, Mishnah 3. The Mishnah before us deals with a case in which a worker receives his meals from his employer, and his employer is an am ha'aretz who cannot be trusted regarding the separation of tithes. How should the worker conduct himself?
The Text of the Mishnah and Its Explanation:
"Po'el she'eino ma'amin l'ba'al habayis" - a worker who does not trust his employer in matters of tithing, since he is an am ha'aretz.
"Notel grogeres achas v'omer: zo v'tesha haba'os achareha asuyos ma'aser al tish'im she'ani ochel" - if they are feeding him grogaros, which are dried figs, he takes one dried fig and declares that it, together with the nine that come after it, will count as the tithe for the ninety that he is about to eat. The ten together with the ninety are one hundred, and the ten (the one and the nine) are a tenth of the whole, and those he may eat, while the remaining ninety are ordinary produce.
"Zo asuyah terumas ma'aser aleihen" - the first dried fig, which was set aside before the other nine, becomes Terumas Ma'aser for the rest of the tithe.
"U'ma'aser sheni ba'acharonah, u'mechulal al hama'os" - the last dried figs that he eats will count as Ma'aser Sheni, and he immediately redeems them onto the coins that he set aside for this purpose.
"V'chosech grogeres achas":
The end result is that one dried fig out of the hundred will not be fit for him to eat. Instead of eating the hundred dried figs that his employer gives him, he will eat only ninety nine. The fig that was set aside as Terumas Ma'aser he cannot eat, and he also cannot take an additional fig in its place, since the employer gave him only one hundred, and taking more would be robbery and theft from him, for the employer maintains that he did in fact separate the tithes.
The Dispute of the Tannaim:
Rabban Shimon ben Gamliel: "Lo yachsoch, mipnei shehu me'ma'et melachtah shel ba'al habayis" - the worker may not deprive himself of eating the hundredth fig, because by doing so he diminishes his strength to work for his employer. He will be slightly weakened, by one hundredth of his strength, and the employer calculated precisely how much food his workers require in order to be able to do their work. Therefore he must go out and buy an additional dried fig from someone else, and make sure that he eats his fill.
Rabbi Yosi: "Lo yachsoch, mipnei shehu tenai beis din" - he need not deprive himself at all, and he may eat the hundredth fig as well, even though he already separated one. This is a condition that beis din established: a chaver who eats at the table of his employer who is an am ha'aretz is permitted to take an additional dried fig, so that he will eat the amount appropriate for him, even though he separated one as Terumas Ma'aser and thereby rendered it unfit for him to eat.
In summary: in this Mishnah we learned the procedure of separation for a worker who does not trust his employer: taking one dried fig and the nine that follow it as the tithe for ninety, the first one as Terumas Ma'aser, and the last ones as Ma'aser Sheni, which is redeemed onto coins. The Tannaim disagreed about the missing fig: according to Rabban Shimon ben Gamliel he does not deprive himself, so that he will not diminish his employer's work, and he must purchase an additional fig; while according to Rabbi Yosi it is a condition of beis din, and he is permitted to take an additional fig from the house.