Mishneh Torah (Rambam) משנה תורה

Where are the head tefillin placed? They should be placed at the point of the skull, the end of the hairline towards the face, the place where a child's brain [can be felt] to pulsate. Care must be taken to position them in the center, so that they will be "between the eyes." The knot should be at the top portion of the neck, the bottom of the skull.

The arm [tefillin] should be tied to one's left arm at the muscle - i.e., the bulging flesh of the arm between the shoulder and the elbow. Thus, if one presses his arm to his ribs, the tefillah will be opposite his heart, thus fulfilling the directive [Deuteronomy 6:6], "And these words... shall be upon your heart."

A person who places the arm tefillah on his palm, or the head tefillah on his forehead, follows the way of the Sadducees. A person who makes his tefillin rounded like a nut does not fulfill the mitzvah at all. A left-handed person puts tefillin on his right hand, since [figuratively,] it is his left hand. If he is ambidextrous, he should place them on his left hand - i.e., his left hand in a literal sense. The places where to tie and place the tefillin were received as part of the oral tradition.

The [absence of the] head tefillah does not preclude [wearing tefillin] on the arm, and similarly, the [absence of the] arm tefillah does not preclude [wearing tefillin] on the head. They are two mitzvot, each one to be considered independently. What blessings are recited? On the head tefillin, one recites: "[Blessed are You...] who has sanctified us with His commandments and commanded us concerning the mitzvah of tefillin." On the arm tefillin, one recites: "[Blessed are You...] who has sanctified us with His commandments and commanded us to put on tefillin."

When does the above apply? When one puts on only one of them. If, however, one puts them both on, one recites only a single blessing, "...to put on tefillin." One should tie the tefillin on one's arm, and afterwards put on the head tefillin. When one removes them, the head tefillin should be removed, and then the arm tefillin.

[After] reciting the blessing, "...to put on tefillin," and tying the tefillin on one's arm, one is forbidden to talk - even to respond to a greeting from one's teacher - until he puts on the head tefillin. If he talks, it is considered to be a transgression. [In such an instance,] one is required to recite the second blessing, "...concerning the mitzvah of tefillin," and then put on the head tefillin.

Whenever a person puts on tefillin - even if he removes them and puts them on several times throughout the day - he should recite a blessing for them. With regard to all mitzvot: one recites a blessing for them before performing them. Therefore, one should recite the blessing for the arm tefillah after placing it on one's muscle, before tying it, since tying it comprises the fulfillment of the mitzvah.

When a person removes his tefillin to place them in a container, he should not place the arm tefillah below and the head tefillah above, because when he wants to put them on, he will encounter the head tefillah first. Thus, he will [be forced to] ignore it and take out the arm tefillah, since one should not put on the head tefillah before the arm tefillah. [This is undesirable because] it is forbidden for a person to ignore one mitzvah and proceed to the fulfillment of another mitzvah. Rather, as soon as a mitzvah comes to a person's hand, he should occupy himself with it. Therefore, a person should place the arm tefillin above, so that he will encounter it first, and thus put on the tefillin in the proper sequence.

A container that was made for tefillin to be placed in and which was used for that purpose becomes holy. It is forbidden to use it for mundane purposes. If a container was prepared for that purpose, but never used for it, or if a container was temporarily used for tefillin, but was not prepared for that purpose, it does not become holy. Rather, it is considered an ordinary article as before. It is forbidden to suspend tefillin. [This applies regardless of whether one suspends them] by their straps or from the tefillah itself. One may, however, suspend the bag in which they are placed.

The time for wearing tefillin is the day and not the night, as [Exodus 13:10] states: "And you shall observe this statute in its appointed time, from day to day." "This statute" refers to the mitzvah of tefillin. Similarly, Sabbaths and holidays are not days on which tefillin [are worn], as [Exodus 13:9] states: "And they shall be a sign for you." Since the Sabbaths and the holidays are themselves signs, [the sign of tefillin is unnecessary]. When does the time to put them on begin? When one can see a colleague standing four cubits away and recognize him. [It continues] until sunset.

It is permitted for a person who put on tefillin before sunset to continue wearing them after nightfall. They may even remain upon him the entire night. This law, however, is not to be taught in public. Instead, everyone should be taught not to wear tefillin at night and to remove them before sunset. A person who puts on tefillin after sunset transgresses a Scriptural prohibition, as [implied by Exodus 13:10]: "And you shall observe this statute... from day to day."

When a person is wearing tefillin in the midst of a journey and the sun sets, marking the commencement of the Sabbath, he should cover them with his hand until he reaches his home and then, remove them. If he is sitting in the house of study and the sun sets, marking the commencement of the Sabbath, he should cover them with his hand until he reaches his home, and then remove them. If there is a house located near the wall [of a city] where they would be safe, he should place them there. If, however, he did not remove his tefillin after sunset because he did not have a place where they would be safe, it is permissible for him to continue wearing them in order to protect them.

All those who are exempt from the obligation to recite the Shema are exempt from the obligation to wear tefillin. If a minor knows [the importance of] guarding his tefillin, his father should obtain tefillin for him, to educate him regarding the performance of mitzvot. A person with stomach problems and anyone who can contain his excretory functions only with difficulty are exempt from the obligation to wear tefillin. [In contrast,] all those ritually impure are obligated to wear tefillin like one who is pure. A person who suffers discomfort, or someone who is disturbed and cannot concentrate his thoughts, is exempt from the obligation to wear tefillin, since a person who wears tefillin is forbidden to divert his attention from them. Priests who are in the midst of [the Temple] service, Levites who chant on the platform, and Israelites while they are attending the Temple [ceremonies] are exempt from the obligation to pray and to wear tefillin.

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.

A person who has tefillin wound around his hand is permitted to sleep with them. [This applies] even to a long sleep. He may eat only a snack while wearing them. If, however, he enters to partake of a regular meal, he should remove them and place them on the table until after he washes his hands [at the conclusion of the meal]. Afterwards, he should put them on and recite grace over his meal while wearing them.

[The following rules apply with regard to a person] wearing tefillin who must use the lavatory: [He should remove his tefillin but,] while he enters, he should not place them in the holes [of the outer wall of the lavatory] which are near the public domain, lest they be taken by passersby. What should he do? Even if he [merely] has to urinate, he should remove his tefillin four cubits away [from the lavatory] and roll them in his clothes like a Torah scroll, holding them near his heart with his right hand. He must take care that the strap does not protrude more than a handbreadth from his hand. Afterwards, he should enter and relieve himself. After leaving the lavatory and walking more than four cubits away, he should put them on.

When does the above apply? In a permanent lavatory where drops [of urine] will not sprinkle upon him. In contrast, in a place that is temporarily being used as a lavatory, one should not enter, [holding tefillin] wound up in one's hand. Instead, one should remove them [outside the lavatory] and give them to a colleague to guard. Urine cannot be expelled [without drops sprinkling] even in a permanent lavatory unless one squats. If [the floor is covered] with soft dust, [drops will not sprinkle] even when one stands. If the floor is hard, one should stand on an incline [and urinate], so that drops will not sprinkle on him.

When a person is wearing tefillin and must relieve himself in the evening, when there would be no time left in the day to put them on again after he finishes, he should not enter a lavatory, [holding them] rolled up in his clothes. What should he do [instead]? He should remove them and place them in their container if it is a handbreadth in size, or in another container which is not specific for them even though it is not a handbreadth in size. He should hold the container in his hand when he enters the lavatory. Similarly, if he needs to relieve himself at night, he should place them in a container and enter the lavatory, holding the tefillin in his hand.

If a person forgot and entered a lavatory while wearing tefillin, he should cover them with his hand until he completes expelling the first issue of feces or urine, and then leave the lavatory, remove the tefillin, return, and complete relieving himself. Were one to interrupt in the midst of expelling the first outburst of feces or urine, he might become very dangerously ill.

If a person forgot and had intercourse while wearing tefillin, he should not hold either the straps or the compartments themselves until he washes his hands. [Then, he should] remove them. [This restriction was instituted] because hands are active.

[The following rules apply to] a person who enters a bathhouse: In the rooms where people stand clothed, it is permitted to put on tefillin. In the rooms where some of the people stand naked and some clothed, one need not remove one's tefillin, nor, at the outset, should one put tefillin on there. In the rooms where [everyone] stands naked, one should remove one's tefillin and, needless to say, one should not put them on.

A person should not walk in a cemetery wearing his head tefillin. Even [outside a cemetery], a person should remove his tefillin if he comes within four cubits of a corpse or a grave, until he distances himself four cubits from them. A person should not put on tefillin [when he is naked]. He must first cover his genitalia and put on his clothes. A person who is carrying a load on his head should remove his head tefillin [and not put it on again] until he puts down his load. It is even forbidden to wear a handkerchief around one's head when wearing tefillin. One may, however, wear a hat over the tefillin.

When tefillin or a Torah scroll are in a room, it is forbidden to engage in sexual relations, unless they are removed or placed into a container, and that container placed into a second container which is not specific to them. If, however, the second container designated for them, even ten containers are considered as a single container. Should a person place [the sacred articles] in two containers, he may place them at the head of his bed, between a cushion and a pillow, as long as they are not under his head, so that he can protect them. [This applies] even if his wife is together with him in bed.

The holiness associated with tefillin is very great. As long as a person is wearing tefillin on his head and arm, he will be humble and God-fearing and will not be drawn to frivolous behavior or empty speech. He will not turn his thoughts to evil matters, but rather will direct his heart to words of truth and justice. Accordingly, a person should try to wear [tefillin] throughout the entire day, for this is the mitzvah associated with them. Among the praises conveyed upon Rav, the student of Rabbenu Hakadosh, was that he was never seen walking four cubits without [reciting words of] Torah, without tzitzit, and without tefillin.

Although it is a mitzvah to wear [tefillin] throughout the entire day, it is most important during prayer. Our Sages declared: "Whoever recites the Shema without tefillin is considered as if he is giving false testimony." Whoever does not wear tefillin transgresses eight positive commandments, for in each of the four passages contained in the tefillin we are commanded to wear both head and arm tefillin. [The rewards for wearing tefillin are also great.] Whoever wears tefillin regularly will live long, as [implied by Isaiah 38:16]: "God is upon them, they shall live."