Maasros, Chapter 3, Mishnah 7. In this mishnah we deal with additional types of structures, and with the question of whether they possess the character of a house that fixes produce for the obligation of maasros. The structures discussed here are temporary, or semi-temporary, and the general rule that emerges from the mishnah is that a temporary structure is not considered a house, and therefore is not among the houses that fix produce for maaser, unlike a permanent home. Nevertheless, there appear to be several fine distinctions here.
The temporary structures in the mishnah:
"Hatzrifin" - a structure built of beams leaning against one another on a diagonal, with no flat roof on top. Its shape may be round or come to a point at an angle, and it consists essentially of poles balanced against each other.
"Haburganin" - a sort of storage shed, a small improvised place built outdoors in order to keep things in it during the harvest season.
"Ha'ilkatiyus" - a structure that we would call a sukkah: four posts and a small roof that provides shade. It is set up in the summer in order to stay cool, but it is not a house, only a shaded shelter for the summer season.
All of these are temporary structures, and therefore they are exempt: food whose processing has been completed and which was brought into them, or passed through them on its way to the permanent house, is not fixed for maaser by its temporary stay in a temporary structure, and one who eats in them a casual meal is exempt.
"Sukkos Ginosar":
Small huts that were built in the area called Ginosar, on the shore of the Kinneret (a town by that name still exists there today). In the era of the Mishnah and Talmud, Ginosar was known as an especially fertile region, rich in fruit crops (and today many bananas are grown there). Since people would stay there, they would put up small huts and shacks during the harvest season.
Regarding these huts the mishnah rules: "Sukkos Ginosar, af al pi sheyesh bahen reichayim v'tarnegolim - peturos" - the huts of Ginosar, even though they contain a millstone and chickens, are exempt. Even if the hut contains features of a more permanent structure - a millstone, that is, a hand mill for grinding wheat into flour, and also chickens, which people do not usually bring into a completely temporary dwelling - it is still a sort of expanded temporary dwelling, a summer house for the harvest season, and this does not change its status. The produce is exempt, since this is not a real house.
"Sukkas hayotzrim":
This is the hut of the potter, who makes earthenware vessels. These huts were built with an inner room in which he would sleep, and an outer room that served as his workshop. Therefore we learn: "haPenimis chayeves" - the inner room is obligated. Since he would live in the inner room, that room is considered a house that fixes produce for maaser. The novelty here is that in the winter, during the rainy season, the potter's hut did not provide sufficient shelter and the potter would not stay there, so it is not a year-round dwelling. Even so, the first tanna holds that it is enough that it is his dwelling for most of the year in order to call it his house and to obligate the produce in maaser.
"V'hachitzonah peturah" - and the outer one is exempt. The outer area, which is the workshop, is exempt, since it is not a house and the potter does not live in it but only works in it. And even though he sometimes sells his wares from there, it is essentially a workshop and not a showroom, and therefore it is exempt.
Rabbi Yose disagrees and says: "Kol she'einah diras yemos hachamah v'diras yemos hageshamim - peturah" - anything that is not a dwelling for the sunny season and a dwelling for the rainy season is exempt. In his view, for a house to be considered a house that fixes produce for maaser, it must be a year-round house; and the potter's hut is a house only when there is no cold and no rain. For this reason Rabbi Yose holds that even the potter's inner room is not a house that fixes produce for maaser. The halachah, however, follows the first tanna.
The sukkah of the festival:
Finally, the Mishnah discusses an actual sukkah, the sukkah of the festival of Sukkos: if a person brings produce into his sukkah, is it fixed for tithing? "Sukkas hechag bechag - Rabbi Yehudah mechayev vaChachamim potrin" - regarding the festival sukkah during the festival, Rabbi Yehudah obligates and the Sages exempt. Rabbi Yehudah holds that produce brought inside is obligated in tithes, while the Sages exempt it entirely.
The root of the dispute lies in their respective positions in Maseches Sukkah:
Rabbi Yehudah: Even though a sukkah is a temporary dwelling, and one lives in it for only seven days, it must be fit and sturdy enough to be lived in all year round. It turns out that the sukkah is a house - one lives in it for only seven days, but it would be possible to live in it all year - and therefore it fixes produce for tithing.
The Sages: A sukkah may be a temporary dwelling that does not stand all year, and it is enough that it withstand the ordinary winds of the festival season. It need not be strong and stable to the point of standing for an entire year, and therefore it does not fix produce for tithing.
The halachah in this case follows the Sages, that an ordinary sukkah does not fix produce for the obligation of tithes.
In summary: In this Mishnah we learned that temporary structures - huts, field watchmen's shelters and summer booths - are not considered a house and do not fix produce for tithing; the booths of Ginosar are exempt even when they contain a millstone and chickens; in a potters' booth the inner one is obligated and the outer one is exempt, and according to Rabbi Yose even the inner one is exempt as long as it is not a dwelling both in the summer and in the rainy season - and the halachah follows the first Tanna; and regarding the festival sukkah, Rabbi Yehudah obligates because the sukkah is fit to serve as a permanent dwelling, while the Sages exempt because it is enough that it withstand the ordinary winds - and the halachah follows the Sages.