Gemara

(Mishnah): A worker may eat a gourd or date, even if it is worth a Dinar;

R. Eliezer Chisma says, a worker may not eat more than his wages;

Chachamim permit this, but we teach a person not to be gluttonous, for then no one will hire him.

Question: Chachamim agree with the first Tana!

Answer #1: They argue about whether or not we teach people not to be gluttonous. The first Tana holds that we do not.

Answer #2: They argue about Rav Asi's law;

(Rav Asi): Even if a worker was hired to harvest only one cluster, he may eat it.

(Rav Asi): Even if a worker harvested only one cluster, he may eat it.

Had Rav Asi taught only the first law, one might have thought that since nothing will remain for the owner, he may eat, but when he will (later) harvest for the owner, he must harvest before eating. Had he taught only the second law, one might have thought that there he may eat for he will later harvest for the owner, but if the owner will be left with nothing, he may not eat.

Answer #3: They argue about Rav's law.

(Rav): In a hidden scroll, Isi ben Yehudah says "Ki Savo b'Cherem Re'echa" permits anyone (not only a worker) to eat.

Rav: This does not allow anyone (i.e. farmers) to survive!

Rav Ashi: I said this in front of Rav Kahana.

Suggestion: Perhaps Isi permits only one who (was not hired, but) works in the land the value of what he eats!

Question: If so, why did Rav object to the law?

Answer: One prefers to choose workers to harvest his land.

Rishonim

The Rif brings the Mishnah.

Nimukei Yosef (DH Masnisin): The Torah authorized a worker to eat to satiation, even if it is more than his wage.

Rambam (Hilchos Sechirus 12:11): A worker may eat gourd or date, even if it is worth a Dinar, even if he was hired only for a sixth of a Dinar. However, we teach a person not to be gluttonous, for then no one will hire him.

Rosh (7:11): Chachamim say that we teach one not to be gluttonous, unlike the first Tana. The Halachah follows Chachamim. We find many Stam Mishnayos that are the opinion of an individual. We say that a Stam Mishnah is R. Meir. 'Chachamim' connotes many. Further, their reasoning is sound. We should teach one what is good for him! Alternatively, Chachamim and the first Tana argue about Rav Asi's law. The Halachah follows Chachamim, who disagree with Rav Asi. One may not eat all that he was hired to harvest. Alternatively, they argue about Isi's law. Rashi says that the first Tana argues with Isi. He permits only a worker. Chachamim agree with Isi. They permit eating more than one's wages, and even if he was not hired at all! I showed that the Halachah follows Chachamim, therefore, the Halachah follows Isi. However, it seems that the first Tana holds like Isi. Just like he permits one to eat for more than his wage, he permits who works just for his meal. Chachamim permits eating more than one's wage, but only if he gets a wage. Rav Ashi merely suggested that perhaps Isi permits only one who works the value of what he eats! He accepted Rav Kahana's response, that one prefers to choose workers to harvest his land.

R. Yonason (in Shitah Mekubetzes): One may eat more than a Dinar if needed for satiation, for the Torah permitted "your satiation." R. Eliezer Chisma forbids more than his wages, for it is not normal to be hired for less than one's satiation. The Torah did not discuss bizarre cases. Chachamim hold that the Torah discusses everyone, even a glutton. However, his friends should teach him not to be gluttonous. The first Tana forbids teaching him this, even giving mere counsel, for we should not uproot what the Torah entitles him to.

Me'iri (DH Afilu): Some say that even if a worker was hired to harvest only one cluster, he may eat the entire cluster. This is unreasonable. If he was hired to harvest a vineyard, one may begin to eat before putting in the owner's basket. It seems that the Rambam explains oppositely.

Poskim

Shulchan Aruch (CM 337:7): A worker may eat more than his wages. If he was hired for a Dinar, he may eat a gourd or a date worth four Dinarim. In any case, we teach him not to do so, lest people refrain from hiring him.

SMA (18): The Gemara and Poskim discuss eating a gourd or date, but the same applies to eating many. The Gemara discusses one due to the opinion that even if he was hired to harvest only one, he may eat it, even if it is more than his wage. Even though the Halachah does not follow that opinion, the Tur and Shulchan Aruch discuss eating one.

Rema: Some say that this is only if he was hired to work the entire day, but if he was hired to harvest just one gourd, he may not eat it, and even if he was hired to work the entire day, he may not eat the first gourd he harvests. Rather, first he puts in the owner's basket, then he eats.

Beis Yosef (DH Yachol): Rashi and the Rosh connote that when the Gemara said 'they argue about Rav Asi's law', it refers to the first version. If so, the Halachah follows the second version. The Tur says that the Halachah does not follow the second version. He learns from the Gemara's explanation why both teachings were needed. It is possible that even if he eats in the first version, he does not eat in the second version. Since the Halachah does not follow the first version, it does not follow the second version. The Rif omitted the Gemara and brought only the Mishnah. He holds that the Halachah follows Chachamim, and not Rav Asi's laws. Also the Rambam rules like Chachamim and omits Rav Asi's laws.

SMA (19): The Rema says 'some say that', even though he and the Mechaber both cite the Tur, because the Beis Yosef said that the Rif and Rambam disagree.

Rebuttal (Shach 3): The Beis Yosef said that Rif and Rambam omitted Rav Asi's laws because they hold that the Halachah does not follow him!

Drishah (7): Surely, if he was hired to harvest only one and he ate it, the owner need not pay him, even if it was worth less than his wage. If he was hired for the entire day, even if he ate more than his wage, his employer must pay his full wage. The Tur holds that since the Gemara said 'they argue about Rav Asi's law' without specifying which, they argue about both. If not; the Gemara should not have brought his second teaching here, especially because it interrupts between the Mishnah and the third explanation of the argument! Rather, the first Tana alludes to both of Rav Asi's laws (he may eat a gourd, even if he was hired to harvest only it or harvests it first).

Gra (7): Rashi and the Rosh connote that Rav Asi's second law does not depend on the argument in the Mishnah. However, the Rif and Rambam omitted it because they hold that it depends on it (so we do not follow it).