GEMARA

19b - Mishnah: If a big mat was made to lie on, it is Mekabel Tum'ah. One may not use it for Sechach. If it was made for Sechach it is Kosher for Sechach and it is not Mekabel Tum'ah.

R. Eliezer says, small and big mats are the same. If they were made to lie on they are Mekabel Tum'ah and are Pasul for Sechach. If they are made for Sechach they are Kosher for Sechach and are not Mekabel Tum'ah.

Inference: The Reisha says that a big mat made to lie on is Mekabel Tum'ah. This implies that if it was made Stam (without specifying) it is for Sechach.

Contradiction: The Seifa says that a mat made for Sechach is Kosher for Sechach. This implies that Stam it is to lie on!

Answer #1: The Seifa discusses a small mat.

Objection: The same contradiction can be asked against R. Eliezer, and he does not distinguish big mats from small!

Answer #2 (Rava): All agree that a big mat made Stam is for Sechach. They argue about a small mat. The first Tana says that Stam it is to lie on, and R. Eliezer says that Stam it is for Sechach.

The first Tana says, a big mat was made to lie on it is Mekabel Tum'ah and Pasul for Sechach. If it was made Stam, it is as if was made for Sechach and it is Kosher for Sechach. R. Eliezer says that small mats are like big mats.

Objection #1 (Abaye): If the first Tana discusses only big mats, R. Eliezer should say 'big and small mats are the same'. But he says 'small and big mats are the same'!

Objection #2 (Abaye): They argue about big mats!

Beraisa: One may use a big reed mattress for Sechach;

R. Eliezer says, one may use it if it is not Mekabel Tum'ah.

Answer #3 (Rav Papa): All agree that a small mat made Stam is to lie on. They argue about a big mat. The first Tana says that Stam it is for Sechach, and R. Eliezer says that Stam it is to lie on.

Question: Why does R. Eliezer say 'if he made it to lie on it is Mekabel Tum'ah'? The same applies to Stam!

He means, Stam it is to lie on, unless it is made specifically for Sechach.

Beraisa: If a mat of rush or reed grass is Gedolah (big), one may use it for Sechach. If it is small, one may not use it for Sechach.

If it is of reeds, if it is Gedolah (Rashi - Gedulah, i.e. plaited), one may use it for Sechach. If it is woven, one may not use it for Sechach.

R. Yishmael b'Rebbi Yosi and R. Dosa say, both of them are valid for Sechach.

R. Chiya and his sons: R. Dosa and Chachamim agree that mats of Usha are Temei'im, and that mats of Tiverya are Tehorim. They argue about mats of other places. R. Dosa is Metaher, because people do not (normally) sit on them. Chachamim are Metamei, because occasionally people sit on them.

RISHONIM

Rif and Rosh (1:37): The Halachah follows the first Tana, like Rav Papa explains. One may use a big mat of rush or reed grass, but not a small one.

Rosh (ibid.): The Rif does not bring the Seifa of the Beraisa because he holds that the Halachah follows R. Dosa. The only distinction within reed mats is between big and small, like in our Mishnah.

Rambam (Hilchos Sukah 5:6): Stam, a small mat of reeds or reed grass or grass is to lie on, so it is Pasul for Sechach unless it was made for Sechach. Stam, a big mat was made for Sechach. One may use it for Sechach unless he made it to lie on.

Rebuttal (Ra'avad): The Beraisa distinguishes between reeds and grass. Even a small mat of reeds may be used if it is plaited, for it is hard and not fit to lie on. If it is woven it is good to lie on, and may be used for Sechach. If it is big, Stam it is for Sechach even if it is woven.

Magid Mishnah: The Rif and Rambam explain that the Beraisa discusses mats made Stam. It is like the first Tana of our Mishnah. Regarding Gedolah (a big mat), the first Tana of the Beraisa says that if it is woven it is Pasul for Sechach. R. Yishmael and R. Dosa permit it even if it is woven. They are like the first Tana of our Mishnah, who only distinguishes between big and small. The Ra'avad holds that the Seifa discusses Gedulah. The first Tana discusses only small mats, and R. Dosa allows even a small mat if it is plaited.

Migdal Oz: The Rif and Rambam do not rule like the Beraisa, rather, like the Mishnah according to Rav Papa. This is because the Gemara discussed the Mishnah until reaching a conclusion, and Rav Papa is Basra.

Question (Lechem Mishneh): Why must the Magid Mishnah say that the Rambam's text says 'Gedolah'? Perhaps it says 'Gedulah' like the text of other Meforshim, nevertheless he explains that they argue about big mats!

Answer (Lechem Mishneh): If the text does not specify 'big', we must say that they argue about small mats, for this was the last matter mentioned.

Rambam (Hilchos Kelim 25:13): A straw mat is Mekabel Tum'as Medras. A mat of reeds or grass is Tahor because it is not fit to lie on. Mats of other materials are Mekabel Tum'ah if they were made to lie on, or if they were made Stam and they are big.

Question (Lechem Mishneh Hilchos Sukah 5:6): In Hilchos Sukah, the Rambam equates reeds, reed grass and grass. Surely, all of these are Mekabel Tum'ah, for otherwise they would always be good for Sechach!

Answer (Lechem Mishneh, ibid.): The Rambam is Metaher mats of reeds and grass only from Medras. They are Mekabel Tum'ah like Klei Etz. Normally, anything made to lie on is Mekabel Tum'as Medras. However, these are not fitting, so Batlah Da'ato Etzel Kol Adam.

Rosh (ibid., citing R. Yeshayah): Mats sold by merchants are not primarily for Sechach. They fill them with wool and make Mechitzos from them. The craftsman makes them for whatever each buyer will do with it. Therefore, it is Mekabel Tum'ah only if the buyer intended to lie on it, even if it is fit to lie on.

Rejection (Rosh, ibid.): It appears that we follow the local practice. The Gemara says that R. Dosa and Chachamim agree that mats of Usha are Temei'im. Even if one asked the craftsman to make it for Sechach it is forbidden, for others will not know this. They will buy mats Stam and use them for Sechach.

POSKIM

Shulchan Aruch (OC 629:6): A mat of reeds, straw, or reed grass, whether it is smooth and fit to lie on or not smooth and not fit to lie on...

Mishnah Berurah (14): It means 'not so fit to lie on.' We say that if it is small, Stam it was made to lie on!

If it is small, Stam it was made to lie on, so it is Mekabel Tum'ah and it is Pasul for Sechach, unless it was specifically made for Sechach.

Sha'ar ha'Tziyon (24): 'Small' means slightly longer than a person's height.

Rema: This means that most people in the city make it for Sechach.

Source (Gra DH d'Hainu): We learn from mats of Usha.

Rebuttal (Taz 7): The Gemara did not say that the Reisha discusses a place where mats are made to lie on and in the Seifa mats are made for Sechach, because this still leaves a contradiction, i.e. what is the law in a place with no fixed practice? Rather, the Mishnah and Gemara discuss places without a fixed practice. The Rosh discusses where there is a fixed practice. There, intent does not matter.

Mishnah Berurah (17,18): It is always forbidden in a place where mats are used to lie on. Where they are used for Sechach it is permitted, unless he intended to lie on it. Where no fixed practice is known, big mats are permitted unless he intended to lie on it, and intent for Sechach helps for small mats. This applies to buying a new mat. However, one may not buy a used mat for Sechach, lest it was used to lie on (Sha'ar ha'Tziyon 32).

Gra (DH Bein): The Shulchan Aruch is like the Rosh (and Rif and Rambam) who say that in the Beraisa Tana'im argue about a Gedolah (big) mat. This is unlike Rashi, who says that they argue about small mats.

Shulchan Aruch: If it is big, Stam it was made for Sechach, so it is Kosher for Sechach, unless it was specifically made to lie on.

Rema: This means that most people in the city make it to lie on.

Kaf ha'Chayim (35): The Bach says that in such a place, even if it was made for Sechach one is not Yotzei in such a Sukah. The Ma'amar Mordechai and Beis Meir say that the Shulchan Aruch does not make the Rosh's decree, and anything made for Sechach is Kosher.

Kaf ha'Chayim (39): The Rashba permits mats made to hang on the walls for Noy.