These sources address the physical construction of tefillin, the requirements for maintaining them throughout daily wear, and the halakhic details that preserve their validity and sanctity. They span from biblical command through rabbinic elaboration to medieval and early modern codification.
חַיָּב אָדָם לְמַשְׁמֵשׁ בִּתְפִלָּיו כָּל זְמַן שֶׁהֵם עָלָיו
Opens as a working sheet — explore, annotate, and export.
What the sources say
The Gemara in Menachot 35b-36a establishes the foundational principle governing a torn tefillin strap: drawing from Devarim 6:8's word *ukshartam*, Rav Yosef rules that the binding must be complete and whole — a makeshift knot does not suffice — and Rav Ashi further rules that a sewn repair is acceptable so long as the stitching is not visible from the outside, deferring to common practice.
The Shulchan Arukh (Orach Chayim 25:4) extends this concern to displacement during wear: if tefillin slip from their proper place and must be adjusted, a new blessing is required upon returning them, though if one did not divert his attention from them throughout, the case is treated more leniently.
Underlying these practical rulings is the theological weight Berakhot 6a assigns to tefillin: they are called a source of strength for Israel because God's name is called upon the wearer through them, which explains why the Rambam (Mishneh Torah, Tefillin 4:1–15) demands that a person touch his tefillin continuously while wearing them and never divert his attention even for a moment, given that their holiness exceeds even that of the tzitz.
The Rambam (Mishneh Torah, Tefillin 1:1–4) grounds the strictness of all these requirements in the fact that tefillin's ten foundational rules are all halachot transmitted to Moshe at Sinai, each one indispensable — so that even a single point of a single letter that is imperfect invalidates the entire set.
דברים ו׳:ח׳
Deuteronomy 6:8
The verse commands binding the words as a sign on the hand and frontlets between the eyes. It is a primary source for tefillin and its enduring role in anchoring identity and divine service.
וּקְשַׁרְתָּ֥ם לְא֖וֹת עַל־יָדֶ֑ךָ וְהָי֥וּ לְטֹטָפֹ֖ת בֵּ֥ין עֵינֶֽיךָ׃
Bind them as a sign on your hand and let them serve as a symbol on your forehead;
recovered from “Exodus 13:9,16”
Exodus 13:9
These verses describe the tefillin-like function of the mitzvah: the sign on the arm and between the eyes is meant to keep God’s teaching and redemption before a person constantly. They provide a biblical foundation for the idea of spiritual durability and remembrance.
מנחות ל״ה ב-ל״ו א
Menachot 35b-36a
This sugya discusses the laws and placement of tefillin, including the practical details that preserve their validity. It is a key Chazal source for how the mitzvah is physically maintained over time.
אַבָּיֵי הֲוָה יָתֵיב קַמֵּיהּ דְּרַב יוֹסֵף, אִיפְּסִיק לֵיהּ רְצוּעָה דִּתְפִילֵּי, אֲמַר לֵיהּ: מַהוּ לְמִיקְטְרֵיהּ? אֲמַר לֵיהּ: ״וּקְשַׁרְתָּם״ כְּתִיב, שֶׁתְּהֵא קְשִׁירָה תַּמָּה. אֲמַר לֵיהּ רַב אַחָא בְּרֵיהּ דְּרַב יוֹסֵף לְרַב אָשֵׁי: מַהוּ לְמִיתְפְּרֵיהּ וְעַיֹּילֵיהּ לִתְפִירָה לְגָאו? אֲמַר: פּוֹק חֲזִי מָה עַמָּא דָּבַר.
§ The Gemara relates: Abaye was sitting before Rav Yosef when the strap of his phylacteries tore. Abaye said to Rav Yosef: What is the halakha as to whether one may tie the strap? Rav Yosef said to him: It is written with regard to phylacteries: “And you shall bind them [ukshartam] for a sign upon your arm” (Deuteronomy 6:8), which teaches that the binding must be complete [keshira tamma], whole and beautiful, and that would not be the case with a makeshift knot. Rav Aḥa, son of Rav Yosef, said to Rav Ashi: What is the halakha as to whether one may sew a strap that tore and insert the stitching inside, so that it is not visible from the outside? Rav Ashi said to him: Go out and see what the people are doing. If the common custom is to do this, it is permitted.
ברכות ו׳ א — ד"ה וּמִנַּיִן שֶׁהַתְּפִילִּין עוֹז הֵם לְיִשְׂרָאֵל —
Berakhot 6a:19
The Gemara teaches that tefillin inspire awe and help protect a person; it also links the presence of tefillin to a Jewish person’s spiritual stature. This is a strong Chazal source for tefillin as a source of inner resilience.
וּמִנַּיִן שֶׁהַתְּפִילִּין עוֹז הֵם לְיִשְׂרָאֵל — דִּכְתִיב: ״וְרָאוּ כׇּל עַמֵּי הָאָרֶץ כִּי שֵׁם ה׳ נִקְרָא עָלֶיךָ וְיָרְאוּ מִמֶּךָּ״. וְתַנְיָא, רַבִּי אֱלִיעֶזֶר הַגָּדוֹל אוֹמֵר: אֵלּוּ תְּפִילִּין שֶׁבָּרֹאשׁ. אֲמַר לֵיהּ רַב נַחְמָן בַּר יִצְחָק לְרַב חִיָּיא בַּר אָבִין: הָנֵי תְּפִילִּין דְּמָרֵי עָלְמָא מָה כְּתִיב בְּהוּ? אֲמַר לֵיהּ ״וּמִי כְּעַמְּךָ יִשְׂרָאֵל גּוֹי אֶחָד בָּאָרֶץ״.
The Gemara asks: And from where is it derived that phylacteries provide strength for Israel? As it is written: “And all the nations of the land shall see that the name of the Lord is called upon you, and they will fear you” (Deuteronomy 28:10). It was taught in a baraita that Rabbi Eliezer the Great says: This is a reference to the phylacteries of the head, upon which the name of God is written in fulfillment of the verse: “That the name of the Lord is called upon you.” Rav Naḥman bar Yitzḥak said to Rav Ḥiyya bar Avin: What is written in the phylacteries of the Master of the world? Rav Ḥiyya bar Avin replied: It is written: “Who is like Your people, Israel, one nation in the land?” (I Chronicles 17:21). God’s phylacteries serve to connect Him, in a sense, to the world, the essence of which is Israel.
משנה תורה, הלכות תפילין ומזוזה וספר תורה ד׳:א׳-ט״ו
Mishneh Torah, Tefillin, Mezuzah and the Torah Scroll 4:1-15
A person must touch his tefillin throughout the time he wears them to maintain continuous attention to them, since their holiness exceeds that of the tzitz due to containing the divine name twenty-one times rather than once; tefillin require a clean body and thus sleeping in them is forbidden except for brief naps if a cloth covers them and no woman is present, which may be done by bending one's head between the knees while sitting.
חַיָּב אָדָם לְמַשְׁמֵשׁ בִּתְפִלָּיו כָּל זְמַן שֶׁהֵם עָלָיו שֶׁלֹּא יַסִּיחַ דַּעְתּוֹ מֵהֶם אֲפִלּוּ רֶגַע אֶחָד. שֶׁקְּדֻשָּׁתָן גְּדוֹלָה מִקְּדֻשַּׁת הַצִּיץ. שֶׁהַצִּיץ אֵין בּוֹ אֶלָּא שֵׁם אֶחָד וְאֵלּוּ יֵשׁ בָּהֶם אֶחָד וְעֶשְׂרִים שֵׁם שֶׁל יוּ״ד הֵ״א בְּשֶׁל רֹאשׁ וּכְמוֹתָן בְּשֶׁל יָד: תְּפִלִּין צְרִיכִין גּוּף נָקִי שֶׁיִּזָּהֵר שֶׁלֹּא תֵּצֵא מִמֶּנּוּ רוּחַ מִלְּמַטָּה כָּל זְמַן שֶׁהֵם עָלָיו. לְפִיכָךְ אָסוּר לִישָׁן בָּהֶם לֹא שְׁנַת קֶבַע וְלֹא שְׁנַת עַרְאַי אֶלָּא אִם הִנִּיחַ עֲלֵיהֶן סוּדָר וְלֹא הָיְתָה עִמּוֹ אִשָּׁה יָשֵׁן בָּהֶם שְׁנַת עַרְאַי. וכֵּיצַד הוּא עוֹשֶׂה. מַנִּיחַ רֹאשׁוֹ בֵּין בִּרְכָּיו וְהוּא יוֹשֵׁב וְיָשֵׁן:
A person should touch his tefillin [from time to time] during the entire time he is wearing them, so that he will not divert his attention from them even for a single moment, for their holiness surpasses that of the tzitz. The tzitz has God's name [written] upon it only once, while the head tefillin - and similarly, the arm tefillin - contain the name י-ה-ו-ה 21 times. tefillin require a clean body; i.e., that one should be careful not to release gas while wearing them. Accordingly, it is forbidden to sleep while wearing them - neither a long sleep nor a nap. If, however, one places a cloth over them and a woman is not with him, one may nap while wearing them. What should he do? Place his head between his knees and sleep while sitting.
Mishneh Torah, Tefillin, Mezuzah and the Torah Scroll 3:4
The passage describes the construction of hand tefillin: a wooden cube with equal length and width and height of approximately one finger-width is wrapped in wet leather; once the leather dries, it is removed and four leather compartments are placed where the wood was, the bottom leather is folded back and sewn at all four corners, and a leather strap-holder is left protruding from the leather.
וְכֵיצַד עוֹשִׂין תְּפִלִּין שֶׁל יָד. לוֹקְחִין עֵץ מְרֻבָּע אָרְכּוֹ כְּרָחְבּוֹ וְיִהְיֶה גָּבְהוֹ כְּאֶצְבַּע אוֹ יָתֵר עַל זֶה מְעַט אוֹ פָּחוֹת מְעַט וּמְחַפִּין אוֹתוֹ בְּעוֹר רָטֹב וּמַנִּיחִין אֶת הָעוֹר עַל הָאִמּוּם עַד שֶׁיִּיבַשׁ וְחוֹלֵץ אֶת הָעוֹר וּמַנִּיחַ אֶת אַרְבַּע הַפָּרָשִׁיּוֹת בִּמְקוֹם הָעֵץ וּמַחֲזִיר מִקְצָת הָעוֹר מִלְּמַטָּה וְתוֹפְרוֹ מֵאַרְבַּע פִּנּוֹתָיו. וּמַנִּיחִין מִן הָעוֹר תּוֹבָר מְקוֹם הָרְצוּעוֹת:
משנה תורה, הלכות תפילין ומזוזה וספר תורה א׳:א׳-ד׳
Mishneh Torah, Tefillin, Mezuzah and the Torah Scroll 1:1-4
Rambam opens the laws of tefillin by defining the mitzvah, its scriptural source, and the basic requirement to wear them. This is a foundational halakhic source for tefillin as an enduring daily practice.
אַרְבַּע פָּרָשִׁיּוֹת אֵלּוּ. שֶׁהֵן (שמות יג א) ״קַדֶּשׁ לִי״. (שמות יג יא) ״וְהָיָה כִי יְבִיאֲךָ יְיָ׳״ שֶׁבְּסֵפֶר וְאֵלֶּה שְׁמוֹת. וּ(דברים ו ד) ״שְׁמַע״. (דברים יא יג) ״וְהָיָה אִם שָׁמוֹעַ״. הֵן שֶׁנִּכְתָּבוֹת בִּפְנֵי עַצְמָן וּמְחַפִּין אוֹתָן בְּעוֹר וְנִקְרָאִין תְּפִלִּין וּמַנִּיחִין אוֹתָן עַל הָרֹאשׁ וְקוֹשְׁרִין אוֹתָן עַל הַיָּד. וַאֲפִלּוּ קוֹצוֹ שֶׁל אוֹת אַחַת מֵאַרְבַּע פָּרָשִׁיּוֹת אֵלּוּ מְעַכֵּב אֶת כֻּלָּן מִן הַתּוֹרָה עַד שֶׁיִּהְיוּ נִכְתָּבוֹת שְׁלֵמוֹת כְּתִקּוּנָן: עֲשָׂרָה דְּבָרִים יֵשׁ בַּתְּפִלִּין כֻּלָּן הֲלָכָה לְמשֶׁה מִסִּינַי וְכֻלָּן מְעַכְּבִין. לְפִיכָךְ אִם שִׁנָּה בְּאַחַת מֵהֶן הֲרֵי הַתְּפִלִּין פְּסוּלוֹת. שְׁנַיִם הֵן בִּכְתִיבָתָן וּשְׁמוֹנָה בְּחִפּוּיָן וּקְשִׁירַת רְצוּעוֹתֵיהֶן. וְאֵלּוּ הֵן הַשְּׁנַיִם שֶׁבִּכְתִיבָתָן. שֶׁכּוֹתְבִין אוֹתָן בִּדְיוֹ וְשֶׁיִּהְיוּ נִכְתָּבִין עַל הַקְּלָף:
Four passages [of the Torah]: Kadesh Li and V'hayah ki y'viacha Ado-nai in the book of Exodus 13:1-10 and 13:11-16) and Shema and V'hayah im shamo'a (Deuteronomy 6:4-9) and 11:13-21) should be written separately and covered with leather. They are called tefillin. They are placed on the head and tied on the arm. According to Torah law, even a mere point of one of the letters from these four passages prevents all of them from being acceptable. All four must be written in the proper manner. There are ten requirements for tefillin. All of them are halachot transmitted to Moses on Mount Sinai. It is necessary to fulfill them all. Therefore, if one made any changes with regard to them, the tefillin are not fit for use: Two of them involve their composition, and eight involve the coverings [placed around the passages] and the tying of their straps. These are the two that involve their composition: a) They must be written in ink; b) They must be written on parchment.
שולחן ערוך, אורח חיים כ״ה — ד"ה צריך שיהיו תפילין עליו בשעת ק"ש
Shulchan Arukh, Orach Chayim 25:4
This siman governs the daily laws of donning tefillin, including order, placement, and conduct while wearing them. It is the central practical code source for sustaining the mitzvah reliably.
צריך שיהיו תפילין עליו בשעת ק"ש ותפלה: אם מניח תפילין כמה פעמים ביום צריך לברך עליהם בכל פעם נשמטו ממקומם וממשמש בהם להחזירן למקומן צריך לברך: הגה ואם מחזיר אחת מהם מברך כמי שמניח תפלה אחת כדלקמן סי' כ"ו [דברי עצמו] הזיזם ממקומם אדעתא להחזירם מיד צריך לברך. הגה וי"א שלא לברך [טור סי' ח'] והכי נהוג וכבר נתבאר לעיל סי' ח' סעיף י"ד מי שמניח תפילין של יד ובירך ובתחלת ההדוק נפסק הקשר של יד והוצרך לעשות קשר אחר אמנם לא הסיח דעתו אינו צריך לחזור ולברך אם הותר של יד קודם הנחה של ראש מהדקן ואין צריך לחזור ולברך אבל אם הניח של ראש ואחר כך הותר של יד מהדק ומברך. מותר לברך על תפילין שאולין ולא על גזולין:
One's tefillin must be upon him during the Shema and Amidah. If one puts on tefillin multiple times in one day, he must recite the blessing on them each time. If they moved from their place [on his head or arm] and he adjusted them to return them to their proper place, he must recite the blessing. (Rem"a: If he returned [only] one of them [back to their proper place], he recites the blessing like one who one only puts on one tefilla - as seen below in siman 26 [this is the Rem"a's own opinion].) If one moved them from their place with the intent to replace them immediately, he still must recite the blessing. Rem"a: There are those who say you should not recite a blessing [Tur - siman 8], and that is the prevalent custom. This was already explained above in siman 8, se'if 14 [If] one was putting on the arm tefillin and recited the blessing, and as he was tightening it, the knot severed and he has to form a new knot, however, he did not take his mind off [of the tefillin] - he does not have to recite the blessing again. If the arm tefillin became loosened before putting on the head tefillin, he should tighten it, and he does not need to recite the blessing again. But if he put on the head tefillin and then the arm tefilling became loosened, then he should tighten it and recite the blessing [again]. It is permitted to recite the blessing on borrowed tefillin, but not on stolen ones.
משנה ברורה ש״ח — ד"ה (כג) כלל - וה"ה כוסות וקערות
Mishnah Berurah 308:24
The passage discusses whether tefillin may be moved on Shabbat, presenting a stringent view that treats them as utensils whose primary function is prohibited (since they cannot be worn on Shabbat), and therefore permits moving them only if necessary for their own protection or relocation, though some authorities allow leniency in cases of pressing need.
(כג) כלל - וה"ה כוסות וקערות וצלוחיות וסכין שע"ג השלחן דתדירין בתשמיש לא חלה עלייהו תורת מוקצה כלל וכאוכלין וכתבי הקודש דמי וע"כ מותרין לטלטלן אפילו שלא לצורך כלל ויש מחמירין אפילו בכלים אלו: (כד) כ"א לצורך - היינו כדי שלא יגנבו או שלא יתקלקלו בחמה וכיוצא בזה והט"ז ומ"א מחמירין וסוברין דתפלין מקרי כלי שמלאכתו לאיסור דהרי אסור להניחן בשבת וכנ"ל בסימן ל"א וע"כ אין לטלטלן כ"א בצריך לגופן [היינו כדי שישמרוהו מהמזיקין] או למקומן ומ"מ במקום הדחק יש להקל כדעה הראשונה וכמו שכתבנו בסימן ל"א בבה"ל ע"ש: