אורח חיים ל״גOrach Chayim 33

Se’if 1א׳

אִם נִתְקַלְקֵל עוֹר שֶׁל שְׁנֵי בָּתִּים מִבָּתֵּי הָרֹאשׁ זֶה אֵצֶל זֶה, אִם הַתְּפִלִּין יְשָׁנִים, פְּסוּלִים, וְאִם הֵם חֲדָשִׁים, כְּשֵׁרִים, כָּל זְמַן שֶׁעוֹר מוֹשַׁב הַבָּתִּים קַיָּם: הַגָּה: גַּם הַבָּתִּים צְרִיכִין לִהְיוֹת קַיָּמִים, אֶלָּא שֶׁנִּקְרְעוּ קְצָת (בֵּית יוֹסֵף) וְיֵשׁ אוֹמְרִים לְהֶפֶךְ, בִּישָׁנִים כְּשֵׁרִים, וּבַחֲדָשִׁים פְּסוּלִים, (רַשִׁ"י וְהָרֹא"שׁ) וְנ"ל דְּיֵשׁ לְהַחְמִיר לִפְסֹל בִּשְׁנֵיהֶם. וְאֵלּוּ הֵם חֲדָשִׁים, כָּל זְמַן שֶׁאִם הָיוּ מוֹשְׁכִים אוֹתָם בִּרְצוּעוֹת, הַבַּיִת מִתְפַּשֵּׁט וְנִפְתָּח נִקְרָא חָדָשׁ, וְאִם אֵינוֹ נִפְתָּח נִקְרָא יָשָׁן, וְאִם נִתְקַלְקְלוּ שְׁנַיִם זֶה שֶׁלֹּא כְּנֶגֶד זֶה, רִאשׁוֹן וּשְׁלִישִׁי כְּשֵׁרִים, אֲפִלּוּ הֵם יְשָׁנִים וְאִם נִתְקַלְקְלוּ ג' בָּתִּים בְּכָל עִנְיָן פְּסוּלִים.

In the case that the leather of two compartments, one next to the other, of the head Tefillin are damaged, if the Tefillin are old they are invalid. [However] if they are new, they are valid as long as the leather as the base of the compartments exists (Rema: the compartments also need to exist unless they are slightly ripped (Beit Yosef) and there are those who say the opposite, that old [Tefillin] would be valid and new [Tefillin] would be invalid [Rashi and ROSH]. And it appears to me, there is to be stringent so that to consider both of them invalid). And these are [what are considered] new: Any time that if you were to pull them by the straps of the head, the compartments would spread out and open; they are new. And if they do not open, they are called old. And if two [compartments of the head] that are not directly next to the other became damaged, [such as] the first and third [compartments], they are valid even if they are old. And if three compartments became damaged, in all cases the [Tefillin] are invalid.

Se’if 2ב׳

אִם נִפְסְקוּ תְּפִירוֹת הַתְּפִלִּין, לְהָרַמְבָּ"ם אִם הָיוּ שְׁתֵּי הַתְּפִירוֹת זוֹ בְּצַד זוֹ, אוֹ שֶׁנִּפְסְקוּ ג' תְּפִירוֹת אֲפִלּוּ זוֹ שֶׁלֹּא כְּנֶגֶד זוֹ, הֲרֵי אֵלּוּ פְּסוּלִים. בַּמֶּה דְּבָרִים אֲמוּרִים, בִּישָׁנִים, אֲבָל בַּחֲדָשִׁים, כָּל זְמַן שֶׁעוֹר מוֹשַׁב הַבָּתִּים קַיָּם, כְּשֵׁרִים. וְאֵלּוּ הֵם חֲדָשִׁים, כָּל שֶׁאוֹחֲזִין מִקְצָת הָעוֹר שֶׁנִּקְרַע תָּפְרוּ, וְתוֹלִין בּוֹ הַתְּפִלִּין, וְהוּא חָזָק, וְאֵינוֹ נִפְסָק. וְאִם אֵין רָאוּי לִתְלוֹת בּוֹ, אֶלָּא הוּא נִפְסָק, הֲרֵי אֵלּוּ יְשָׁנוֹת: הַגָּה: וְיֵשׁ אוֹמְרִים דְּבַחֲדָשִׁים פְּסוּלִים, וּבִישָׁנִים כְּשֵׁרִים (רַשִׁ"י וְהַטּוּר וְהָרֹא"שׁ) וְטוֹב לָחוּשׁ לִשְׁתֵּי סְבָרוֹת כֵּן נִרְאֶה לִי:

If the stitching of the Tefillin was severed... [according] to the Rambam, if the two stitchings were one opposite the other, or if three stitching were severed... even if one was not opposite the other, they are invalid. In what [case] are we referring to? Old ones. But new ones, as long as the leather at the base of the compartments is intact, they are valid. And these are [what are considered] new: Any that [if you were] to hold part of the leather whose stitching was severed and suspend the Tefillin (by the part you are holding) and it is strong [to hold it] and it does not sever. And if it is not fitting to be suspended, rather it severs... then these [are considered] old one. Rema: And some say that by new ones, they are invalid and by old ones, they are valid [Rashi, and the Tur, and the Rosh]. And it is better to be concerned for the two opinions as were mentioned above.

Se’if 3ג׳

עוֹר הָרְצוּעוֹת צָרִיךְ שֶׁיִּהְיֶה מֵעוֹר בְּהֵמָה חַיָה וְעוֹף הַטְּהוֹרִים, וְצָרִיךְ שֶׁיִּהְיֶה מְעֻבָּד לִשְׁמוֹ. רְצוּעוֹת בֵּין מֵעוֹר בֵּין מִקְּלָף כְּשֵׁרוֹת. הֲלָכָה לְמֹשֶׁה מִסִינַי שֶׁיְּהוּ הָרְצוּעוֹת שְׁחֹרוֹת מִבַּחוּץ, אֲבָל מִצַּד פְּנִים יַעֲשֶׂה מֵאֵיזֶה צֶבַע שֶׁיִּרְצֶה, חוּץ מֵאָדֹם, שֶׁמָּא יֹאמְרוּ שֶׁמִּדָּם חֲטָטָיו נִצְבְּעוּ וְהֶאֱדִימוּ.

The leather [that's used] for the straps must be from skin of a kosher domesticated animal, wild animal, or bird. And they must be processed for the sake of the mitzvah. Straps, whether they come from the skin or from parchment, are valid. It is a law passed to Moshe on Sinai that the straps must be black on the outside, but on the inside they may be any color that one wishes except for red. For [people] might [see it and] say that from the blood of the scabs [of the wearer] they were dyed.