Halacha

הלכה א
הַמַּפָּץ הוּא הַמַּחְצֶלֶת שֶׁאוֹרְגִין אוֹתָהּ מִן הַחֲבָלִים וּמִן הַסּוּף וּמִן הַגֹּמֶא וְכַיּוֹצֵא בָּהֶן. וְאֵין הַמַּפָּץ בִּכְלַל כֵּלִים הָאֲמוּרִין בַּתּוֹרָה וְאַף עַל פִּי כֵן מִתְטַמֵּא הוּא בְּמִדְרָס דִּין תּוֹרָה שֶׁהֲרֵי רִבָּה הַכָּתוּב (ויקרא טו ד) "כָּל הַמִּשְׁכָּב" וְזֶה רָאוּי לְמִשְׁכָּב וְעָשׂוּי לוֹ. וְכֵן מִתְטַמֵּא בְּמֵת וּבִשְׁאָר טֻמְאוֹת מִדִּבְרֵיהֶן כְּכָל פְּשׁוּטֵי כְּלֵי עֵץ כְּמוֹ שֶׁבֵּאַרְנוּ. וְזֶה כְּלָל גָּדוֹל שֶׁכָּל הַמִּתְטַמֵּא בְּמִדְרָס מִתְטַמֵּא בִּשְׁאָר טֻמְאוֹת:
כסף משנה
1.
A mapatz is a mat made by interweaving cords, reeds, grasses, or the like. A mapatz is not one of the keiliim mentioned by the Torah. Nevertheless, it is susceptible to the impurity associated with the support of a zav according to Scriptural Law. The rationale is that Leviticus 15:4 states "All surfaces on which one lies," expanding the category of articles susceptible to impurity. A mat is thus included, because it is fit to lie on and is indeed made for that purpose. Similarly, it contracts impurity from contact with a human corpse and other sources of impurity according to Rabbinic Law, like all other flat wooden keiliim, as we explained. This is a great general principle: Any entity that is susceptible to the impurity associated with the support of a zav is susceptible to other types of impurity.

הלכה ב
כְּבָר בֵּאַרְנוּ שֶׁהַבֶּגֶד מִתְטַמֵּא בְּשָׁלֹשׁ עַל שָׁלֹשׁ כְּמוֹ שֶׁבֵּאַרְנוּ בִּשְׁאָר טֻמְאוֹת. וּבִשְׁלֹשָׁה טְפָחִים עַל שְׁלֹשָׁה טְפָחִים לְמִדְרָס:
כסף משנה
2.
We already explained that a piece of cloth three fingerbreadths by three fingerbreadths is susceptible to other types of impurity and one three handbreadths by three handbreadths is susceptible to the impurity associated with the support of a zav.

הלכה ג
הַשַּׂק שִׁעוּרוֹ אַרְבָּעָה טְפָחִים עַל אַרְבָּעָה טְפָחִים. הָעוֹר חֲמִשָּׁה עַל חֲמִשָּׁה. הַמַּפָּץ שִׁשָּׁה עַל שִׁשָּׁה בֵּין לְמִדְרָס בֵּין לִשְׁאָר הַטֻּמְאוֹת. וּפָחוֹת מִן הַשִּׁעוּרִין הָאֵלּוּ טְהוֹרִין מִכְּלוּם. בַּמֶּה דְּבָרִים אֲמוּרִים בְּקֶרַע אֶחָד מֵהֶן שֶׁנִּקְרַע בְּלֹא כַּוָּנָה. אֲבָל הַקּוֹצֵץ בְּכַוָּנָה וְקִצֵּץ אֲפִלּוּ טֶפַח עַל טֶפַח לְמוֹשָׁב אוֹ שְׁלֹשָׁה טְפָחִים עַל שְׁלֹשָׁה טְפָחִים לְמִשְׁכָּב הֲרֵי זֶה מִתְטַמֵּא בְּמִדְרָס. בֵּין שֶׁהָיָה הַטֶּפַח עַל טֶפַח שֶׁקִּצֵּץ אוֹ הַשְּׁלֹשָׁה בֶּגֶד אוֹ שַׂק אוֹ עוֹר אוֹ מַפָּץ. וְכֵן הַמְקַצֵּעַ מֵאֶחָד מֵהֶן לַאֲחִיזָה כְּדֵי שֶׁיֹּאחַז בּוֹ בְּיָדוֹ כְּדֶרֶךְ שֶׁעוֹשִׂין קוֹצְצֵי תְּאֵנִים שֶׁלֹּא יִזּוֹקוּ אֶצְבְּעוֹתֵיהֶן הֲרֵי זֶה טָמֵא בְּכָל שֶׁהוּא. וְהוּא שֶׁלֹּא יִהְיֶה פָּחוֹת מִשָּׁלֹשׁ עַל שָׁלֹשׁ שֶׁכָּל פָּחוֹת מִשָּׁלֹשׁ אֶצְבָּעוֹת טָהוֹר מִכְּלוּם:
כסף משנה
3.
The measure for a cloth of goats' hair to be susceptible to impurity is four handbreadths by four handbreadths; for leather, five handbreadths by five handbreadths, for a mat, six handbreadths by six handbreadths, both with regard to the impurity associated with the support of a zav and with regard to other types of impurity. Anything smaller than these measures is pure on all accounts.
In which instance does the above apply? When a piece of fabric was torn from such a cloth unintentionally. If, however, one intentionally cuts a piece off, even if it is merely one handbreadth by one handbreadth for a seat or three handbreadths by three handbreadths for a surface on which one lies, it is susceptible to the impurity associated with the support of a zav. This applies whether the piece one handbreadth by one handbreadth or three handbreadths by three handbreadths was a cloth, from goats' hair, leather, or a mat. Similarly, if one sets aside a fragment of such fabrics to hold, i.e., to hold in one's hand as the harvesters of figs do so that their fingers will not be damaged, the fragment is impure whatever its size, provided it is not less than three fingerbreadths by three fingerbreadths. For any fragment less than three fingerbreadths by three fingerbreadths is pure under all conditions.

הלכה ד
הַמְחַבֵּר שְׁנֵי טְפָחִים מִן הַבֶּגֶד וּמִן הַשַּׂק טֶפַח שְׁלֹשָׁה מִן הַשַּׂק וְאֶחָד מִן הָעוֹר אַרְבָּעָה מִן הָעוֹר וְאֶחָד מִן הַמַּפָּץ הֲרֵי זֶה טָהוֹר מִן הַמִּדְרָס. אֲבָל אִם חִבֵּר חֲמִשָּׁה טְפָחִים מִן הַמַּפָּץ וְאֶחָד מִן הָעוֹר אַרְבָּעָה מִן הָעוֹר וְאֶחָד מִן הַשַּׂק שְׁלֹשָׁה מִן הַשַּׂק וְאֶחָד מִן הַבֶּגֶד הֲרֵי זֶה טְמֵא מִדְרָס זֶה הַכְּלָל כָּל שֶׁהִשְׁלִים שִׁעוּרוֹ בְּחָמוּר מִמֶּנּוּ טָמֵא מִן הַקַּל טָהוֹר:
כסף משנה
4.
If one joins two handbreadths from a cloth to one handbreadth from a cloth of goats' hair, three handbreadths from a cloth of goats' hair to one handbreadth from leather, four handbreadths from leather and one from a mat, the article is pure. If, by contrast, one joined five handbreadths from a mat and one from leather, four handbreadths from leather and one from goats' hair, three handbreadths from goats' hair and one from cloth, the article is susceptible to the impurity associated with the support of a zav.
This is the general principle: Whenever one completes the minimum measure with a substance governed by a more stringent law, it is susceptible to impurity. If it is completed] with a substance governed by a less stringent law, it is pure.

הלכה ה
בְּלוֹיֵי נָפָה וּכְבָרָה שֶׁהִתְקִינָן לִישִׁיבָה טְהוֹרִין וְאֵינָן מְקַבְּלִין טֻמְאָה עַד שֶׁיְּקַצְּצֵם וְאַחַר כָּךְ יִהְיוּ כְּמַפָּץ:
כסף משנה
5.
When a sifter or a sieve that became worn out was adjusted to be used as a seat, it is pure. They are not susceptible to impurity until the edges are cut and straightened. Afterwards, it is considered as a mat.

הלכה ו
חָלוּק שֶׁל קָטָן אֵינוֹ מִתְטַמֵּא בְּמִדְרָס עַד שֶׁיִּהְיֶה בּוֹ כְּשִׁעוּר שְׁלֹשָׁה טְפָחִים עַל שְׁלֹשָׁה טְפָחִים וְנִמְדָּד כָּפוּל כִּבְרִיָּתוֹ. וְאֵלּוּ נִמְדָּדִין כְּפוּלִין בְּגָדִים שֶׁמַּלְבִּישִׁין אוֹתָן עַל הָרַגְלַיִם וְעַל הַשּׁוֹקַיִם וְאֶת הָרֹאשׁ וְהַמִּכְנָסַיִם וְהַכּוֹבַע וְהַכִּיס שֶׁל פֻּנְדָּא וּמַטְלִית שֶׁתְּלָאָהּ עַל הַשָּׂפָה אִם פְּשׁוּטָה נִמְדֶּדֶת פְּשׁוּטָה וְאִם כְּפוּלָה נִמְדֶּדֶת כְּפוּלָה:
כסף משנה
6.
A cloak of a child is not susceptible to impurity unless it comprises the minimum measure: three handbreadths by three handbreadths. Both of its sides are measured as one, for that is the way it is made.
These are the garments whose sides are measured as one: garments that are worn over the feet, the shins, and the head, pants, undergarments with pockets. When a patch was sewn over the edge of a garment, if it was extended to its full length, it is measured as its full length. If it was folded over, it is measured as it is folded over.

הלכה ז
הַבֶּגֶד שֶׁאָרַג שְׁלֹשָׁה עַל שְׁלֹשָׁה נִטְמָא בְּמִדְרָס וְאַחַר כָּךְ הִשְׁלִים אֶת כָּל הַבֶּגֶד כֻּלּוֹ מִדְרָס. נָטַל חוּט אֶחָד מִתְּחִלָּתוֹ טָהַר מִן הַמִּדְרָס אֲבָל טָמֵא מַגַּע מִדְרָס וַהֲרֵי הוּא רִאשׁוֹן כִּכְלִי שֶׁנָּגַע בְּמִדְרָס. נָטַל חוּט אֶחָד מִתְּחִלָּתוֹ וְאַחַר כָּךְ הִשְׁלִים אֶת כָּל הַבֶּגֶד כָּל הַבֶּגֶד טָמֵא מַגַּע מִדְרָס. וְכֵן בֶּגֶד שֶׁנֶּאֱרַג בּוֹ שָׁלֹשׁ אֶצְבָּעוֹת עַל שָׁלֹשׁ אֶצְבָּעוֹת וְנִטְמָא בְּמֵת וְאַחַר כָּךְ הִשְׁלִים עָלָיו אֶת כָּל הַבֶּגֶד הַבֶּגֶד כֻּלּוֹ טְמֵא מֵת. נָטַל חוּט אֶחָד מִתְּחִלָּתוֹ טָהַר מִטְּמֵא מֵת. אֲבָל טְמֵא מַגָּע טְמֵא מֵת. נָטַל חוּט אֶחָד מִתְּחִלָּתוֹ וְאַחַר כָּךְ הִשְׁלִים אֶת כָּל הַבֶּגֶד הַכּל טָהוֹר. וְלָמָּה יִהְיֶה הַכּל טָהוֹר מִפְּנֵי שֶׁאָמְרוּ שָׁלֹשׁ עַל שָׁלֹשׁ שֶׁנִּתְמַעֲטָה טְהוֹרָה מִכְּלוּם אֲבָל שְׁלֹשָׁה עַל שְׁלֹשָׁה שֶׁנִּתְמַעֲטָה אַף עַל פִּי שֶׁטָּהֲרָה מִן הַמִּדְרָס הֲרֵי הִיא טְמֵאָה בְּכָל הַטֻּמְאוֹת:
כסף משנה
7.
When exactly three handbreadths by three handbreadths of a garment were woven and it contracted the impurity associated with the support of a zav and afterwards, the entire garment was completed, the entirety of the garment is impure on that level of impurity. If one removed one strand from the beginning of the original garment, it is no longer considered in that category of impurity. It is, however, impure like an article that came in contact with a support that contracted the impurity of a zav. It is a primary derivative, like a k'li that touched such a support. If one removed one strand from the beginning of the original garment and then completed the entire garment, the entire garment is impure like an article that came in contact with a support that contracted the impurity of a zav.
Similarly, when three fingerbreadths by three fingerbreadths of a cloth were woven, it contracted the impurity associated with a human corpse, and then one completed the entire garment, the entire garment is impure with the impurity associated with a human corpse. If one removed one strand from the beginning of the original garment, it is no longer considered in that category of impurity. It is, however, impure like an article that came in contact with such impurity. If one removed one strand from the beginning of the original garment and then completed the entire garment, the entire garment is pure.
Why is the entire garment pure? Because it was said that when the size of a cloth three fingerbreadths by three fingerbreadths was reduced, it is pure entirely. By contrast, although a cloth three handbreadths by three handbreadths whose size was reduced is no longer susceptible to the impurity associated with the support of a zav, it is susceptible to other types of impurity.

הלכה ח
מַטְלִית שֶׁהִיא מִדְרָס וּטְלָאָהּ עַל הַקֻּפָּה אוֹ עַל הָעוֹר נַעֲשָׂה הַכּל רִאשׁוֹן לְטֻמְאָה. הִפְרִישׁ אֶת הַמַּטְלִית הֲרֵי הַקֻּפָּה אוֹ הָעוֹר רִאשׁוֹן מִפְּנֵי שֶׁנָּגְעוּ בַּמִּדְרָס וְהַמַּטְלִית טְהוֹרָה שֶׁכֵּיוָן שֶׁטְּלָאָהּ וְהִפְרִישָׁהּ בָּטְלָה. טְלָאָהּ עַל הַבֶּגֶד אוֹ עַל הַשַּׂק נַעֲשָׂה הַכּל מִדְרָס וַהֲרֵי הַכּל אַב טֻמְאָה. הִפְרִישָׁהּ הֲרֵי הַבֶּגֶד אוֹ הַשַּׂק רִאשׁוֹן שֶׁהֲרֵי נָגַע בַּמִּדְרָס וְהַמַּטְלִית אַב טֻמְאָה כְּשֶׁהָיְתָה שֶׁאֵינָהּ בְּטֵלָה עַל הָאָרִיג. תָּפַר הַמַּטְלִית עַל הַבֶּגֶד כְּשֶׁטְּלָאָהּ מֵרוּחַ אַחַת אוֹ מִשְּׁתֵי רוּחוֹת כְּמִין גַּאם אֵינוֹ חִבּוּר וְלֹא נַעֲשָׂה הַכּל אָב אֶלָּא מַגַּע מִדְרָס בִּלְבַד. תְּפָרָהּ מִשְּׁתֵי רוּחוֹת זוֹ בְּצַד זוֹ הֲרֵי הִיא חִבּוּר וְנַעֲשָׂה הַכּל אָב:
כסף משנה
8.
When a patch that had contracted the impurity associated with a support of a zav was attached to a basket or a hide, the entire entity is considered as a primary derivative of impurity. If, afterwards, one separated the patch from it, the basket or the hide remain a primary derivative, because they came in contact with a support. The patch, however, is pure, since it was attached and detached, its identity was subsumed to that of the basket or hide.
If he attached the patch to a cloth of linen or wool or of goats' hair, the entire cloth is considered as a primary source of the impurity associated with a zav. If, afterwards, the patch was separated, the cloth or the goats' hair is considered as a primary derivative and the patch is a primary source of impurity, as it was originally. For it is not subsumed to the weave.
When he attached the impure patch to the garment, if he sewed it on one side or even on two sides, but like a gamma, it is not considered as joined together, nor is the entire garment considered as a primary source of impurity. Instead, it is only considered to have come in contact with a support of a zav. If it was sewn on two sides, one opposite the other, it is considered as joined to the garment, and the entire garment is considered as a primary source of impurity.

הלכה ט
שְׁלֹשָׁה עַל שְׁלֹשָׁה שֶׁנִּטְמָא בְּמִדְרָס וְאַחַר כָּךְ נֶחְלַק טָהַר מִן הַמִּדְרָס וְאֵין בִּקְרָעִים אֵלּוּ טֻמְאָה כְּלָל וְהִנָּם כְּשִׁבְרֵי כְּלִי שֶׁנִּטְמָא. אֲבָל בֶּגֶד שֶׁנִּטְמָא בְּמִדְרָס וְקָרַע מִמֶּנּוּ שָׁלֹשׁ אֶצְבָּעוֹת עַל שָׁלֹשׁ אֶצְבָּעוֹת אוֹתוֹ הַקֶּרַע טָהַר מִן הַמִּדְרָס אֲבָל טְמֵא מַגַּע מִדְרָס שֶׁבְּעֵת פְּרִישָׁתוֹ מִן הַבֶּגֶד הַגָּדוֹל נִטְמָא בְּמַגָּע:
כסף משנה
9.
When a cloth three handbreadths by three handbreadths that had contracted the impurity associated with a support of a zav was afterwards divided, it is purified and the remnants are not impure at all. Their status is like that of the broken pieces of a k'li that had contracted impurity. When, by contrast, one cut a piece three fingerbreadths by three fingerbreadths from a large cloth that had contracted the impurity associated with a support of a zav, that piece has been purified from that level of impurity. It, nevertheless, is impure, as an object that touched such a support, because at the time it was separated from the larger cloth, it contracted that level of impurity through contact with the impure cloth.

הלכה י
סָדִין שֶׁנִּטְמָא בְּמִדְרָס וְאַחַר כָּךְ עֲשָׂאָהוּ פָּרֹכֶת טָהַר מִן הַמִּדְרָס. וּמֵאֵימָתַי הוּא טָהֳרָתוֹ מִן הַמִּדְרָס מִשֶּׁיִּקְשֹׁר בּוֹ הַלּוּלָאוֹת שֶׁהוּא נִתְלֶה בָּהֶן כִּשְׁאָר הַפָּרוֹכוֹת:
כסף משנה
10.
When a cloak that had contracted the impurity associated with a support of a zav was afterwards made into a curtain, it is purified from that impurity.
When is it purified from that impurity? When one attaches to it loops from which it will be hung like other curtains.

הלכה יא
טַלִּית שֶׁהִיא מִדְרָס וְהִטְבִּילָהּ וְקֹדֶם שֶׁיַּעֲרִיב שִׁמְשָׁהּ הִתְחִיל לִקְרֹעַ מִמֶּנָּה קֶרַע כֵּיוָן שֶׁנִּקְרַע בָּהּ רֻבָּהּ שׁוּב אֵינָהּ חִבּוּר וְטָהֲרָה כֻּלָּהּ אַף עַל פִּי שֶׁעֲדַיִן נִשְׁתַּיֵּר בָּהּ כְּדֵי מַעֲפֹרֶת שֶׁלֹּא נִקְרַע שֶׁהֲרֵי הוּא קוֹרֵעַ וְהוֹלֵךְ. בַּמֶּה דְּבָרִים אֲמוּרִים בִּטְבוּלַת יוֹם שֶׁכֵּיוָן שֶׁלֹּא חָס עָלֶיהָ לְהַטְבִּילָהּ כָּךְ לֹא יָחוּס לִקְרֹעַ אֶת כֻּלָּהּ וּלְפִיכָךְ טָהֲרָה כֻּלָּהּ:
כסף משנה
11.
When a garment that had contracted the impurity associated with a support of a zav was immersed in a mikveh, but before nightfall that day, one began tearing fragments from it, once the majority of it was torn, it is no longer considered as joined together and the entire garment is pure even though there still remained a portion large enough for a scarf that was not torn. The rationale is he has the intent to continue to tear it.
With regard to what does the above apply? With regard to an article that was immersed that day. Since he did not care for it enough not to refrain from immersing it, it can be assumed that he will also not care for it enough not to refrain from tearing it in its entirety. Therefore, the entire garment is pure.

טהרה הלכות כלים פרק כג
Taharah Kelim Chapter 23