In the previous section we studied a Mishnah dealing with the number of items that are not to be considered leket or shichechah: once they reach a certain quantity, they are no longer regarded as gifts to the poor, and they belong to the owner. Mishnah 6 before us addresses a different question - not the number of items but the size of a single item: can something large be considered shichechah.
"Ha'omer sheyesh bo sasayim ushcheicho":
The Mishnah opens: "Ha'omer sheyesh bo sasayim ushcheicho - eino shichechah" - a sheaf containing two se'ah that was forgotten is not shichechah. An omer is a bundle of grain, and when it contains sasayim - two se'ah, a very large quantity - and the owner forgot it in the field, it is not considered shichechah. The reason will emerge later in the Mishnah: it is simply too large to be considered shichechah.
Two sheaves containing two se'ah:
What is the law when we are not dealing with a single sheaf of two se'ah, but with two sheaves that together contain two se'ah? On this there is a dispute:
Rabban Gamliel says: it belongs to the owner - this is not shichechah, and it belongs to the owner of the field.
And the Sages say: it belongs to the poor - this is shichechah. The rule of two se'ah was stated specifically regarding a single sheaf, and once we are dealing with two sheaves it does not apply.
Rabban Gamliel's argument:
Rabban Gamliel begins by asking the Sages a question from which he will build a kal vachomer: "Vechi merov ha'amarim yafeh kocho shel ba'al habayis o hura kocho?" - does a greater number of sheaves strengthen the owner's claim or weaken it? In other words, as we saw in the previous Mishnah dealing with the number of bundles: does an increase in the number of bundles strengthen the owner's power to keep the item, or does it weaken his claim?
The Sages answered him with something everyone agrees to: "Yafeh kocho" - his claim is strengthened. A greater number of bundles certainly strengthens the owner's power to keep the item, and it is not considered leket or shichechah - and on this point there is no difference between the opinion of Beis Shammai and that of Beis Hillel.
From here Rabban Gamliel built his kal vachomer: "Umah im bizman shehu omer echad uvo sasayim - eino shichechah, shnei amarim uvahem sasayim - eino din shelo yehu shichechah?" If in a case that all agree upon, a single sheaf containing two se'ah, it is not shichechah - then two sheaves containing two se'ah, where the greater number of sheaves strengthens the owner's claim, all the more so should they not be shichechah.
The Sages' reply:
The Sages rejected the kal vachomer and refuted the reasoning behind it: "Lo, im amarta be'omer echad shehu kegadish - tomar bishnei amarim shehen kichrichos" - no, if you say this about one sheaf, which is like a stack, will you say the same about two sheaves, which are like bundles? A single sheaf of two se'ah is not considered shichechah because it looks like a heap and a large stack, and it is no longer in the category of a bundle at all; whereas two sheaves look like bundles, and bundles they are.
It emerges that the factor that removes the item from the category of shichechah is not the number of sheaves but the fact that it is one large item. In the view of the Sages, a greater number of bundles does not help here at all, and it even detracts from the claim that the item is in the owner's possession: the two se'ah belong to the owner only when they form one enormous bundle.
In summary: in this Mishnah we learned that a single sheaf containing two se'ah that was forgotten is not shichechah. Regarding two sheaves that together contain two se'ah, Rabban Gamliel, who awards them to the owner on the strength of a kal vachomer from the greater number of sheaves, and the Sages, who award them to the poor, are in dispute. As a matter of halachah the Sages refuted the kal vachomer: the exemption from shichechah stems from the fact that a sheaf of two se'ah resembles a stack rather than a bundle, whereas two sheaves are bundles.