According to the Talmud, Avraham’s firm refusal to share in the spoils of
war with the King of Sodom, and his proud, righteous proclamation that
Hashem alone is his benefactor, had far-reaching results. In the merit of
his statement, If so much as a thread to a shoe strap, Hashem rewarded his
descendants with the mitzvah of retzuah shel tefillin (tefillin straps). The
term “retzuah shel tefillin” signifies that aside from the tefillin
themselves, there is a special significance to the retzuos, the straps, of
the tefillin. Some relevant information:
Question: What is the correct length for the retzuos?
Discussion: The minimum length of the strap of the tefillin shel yad must be
at least long enough to encircle one’s upper arm, form the kesher and
tighten it, extend downwards to the middle finger and encircle it three
times. It is preferable and customary, however, to have a retzuah long
enough so that it can be wrapped around the arm seven times.
The retzuah for the tefillin shel rosh must be at least long enough to
encircle one’s head with an additional two tefachim [approximately 7-8
inches] on each side. It is preferable and customary to have longer
retzuos, extending to the midsection of the body, with the right one longer
than the left one.
Question: How wide must the retzuos be?
Discussion: While contemporary retzuos are usually fifteen millimeters wide,
the minimum width of the retzuah is eleven millimeters. Under
extenuating circumstances, one may put on tefillin (and recite the
blessings) even if the retzuah is only nine millimeters wide. It is
important to be aware that from wear and tear, a retzuah will frequently
narrow at the point where it is tightened and fall short of the required
Question: How black must be the retzuos be?
Discussion: The outside of the retzuos (i.e., the side that faces up,
away from the skin) must be painted black, “black as a raven,”
l’chatchilah. To obtain this intense shade of black, the retzuos must
be blackened, allowed to dry, and blackened a second and third time.
B'diavad, the retzuos are kosher as long as they can be considered black.
Even if they appear to be closer to dark blue or gray, they are still
When the retzuos age and the blackening peels off, they should be blackened
again. [Special care must be taken at the point of tightening, since
frequently, the paint peels off just at that spot. ] L’chatchilah, the
retzuos should be reblackned so that not even a speck of white appears. But
the retzuos are still kosher as long as they appear black to the naked
eye, even though they have tiny white flecks or cracks, especially if
the white spots are on the part of the retzuos which are longer than the
minimum length and width described earlier.
Question: May the retzuos be blackened by a woman or a minor?
Discussion: The blackening must be done l'shem mitzvas tefillin. One
who forgot to state explicitly or to bear in mind that he is blackening them
lishmah, must repaint the retzuos with the proper concentration. A
woman may blacken the retzuos. A minor may do so only if an adult is
supervising him while instructing him to blacken them l'shem mitzvas
tefillin. [The retzuos may be blackened at night. ]
Question: Is one required to remove his wristwatch before binding the
tefillin straps around his arm?
Discussion: Tefillin must be placed directly on the arm and head without any
interference or barrier (chatzitzah). Although the Rama rules that this
applies only to the tefillin (boxes) themselves, but not to the straps which
are bound around the head or the arm, others are more stringent. Most
poskim hold that any part of the straps which is related to the knotting of
the tefillin, both shel rosh and shel yad, must be put directly on the body
without any interference. It follows, therefore, that one is not required to
remove his wristwatch before binding the straps around his lower arm, since
that area is not at all related to the knotting of the tefillin. Still
many people are accustomed to remove their wristwatch before putting on
tefillin, and it is proper that they continue doing so, since there are
some poskim who are more stringent and recommend that there be no
obstruction on any part of the arm or headwhere the tefillin retzuos are
Question: Is long hair considered a chatzitzah between the head and the
tefillin shel rosh?
Discussion: Some poskim are very strict on this issue. They rule that
long hair is not a natural outgrowth of the body and it constitutes a
chatzitzah. Other poskim consider hair to be an extension of the body
no matter what its length. The Aruch ha-Shulchan rules that hair in its
natural place of growth is not considered a chatzitzah, and that it has
become customary to allow tefillin to be placed on top of hair of any
length. He adds, however, that hair which is combed over to the area where
the tefillin box is placed does constitutes a chatzitzah, since that hair is
not in its natural place of growth.
One who wears a toupee and is embarrassed to remove it in shul may put
tefillin over it, but the blessing over the tefillin shel rosh may not be
recited. When he comes home, he should remove the toupee, put his tefillin
directly on his head, and recite the blessing. [If a toupee is attached to
his head, then tefillin may be put over it with a blessing.]
Question: Is one obligated to fast if his tefillin fall to the ground?
Discussion: It is customary to fast if one accidentally or negligently
dropped his tefillin shel yad or shel rosh and it fell to the ground or the
floor. [If the retzuah alone hit the floor, or if the tefillin fell
onto a table or a chair, fasting is not required.] Preferably, the fast
should take place on the day that the tefillin fell to the ground.
There are some cases of dropped tefillin where the poskim did not require
fasting but advised that charity be given instead. In certain, limited
cases, the poskim recommend a ta’anis dibbur instead of fasting, or
additional hours of Torah study, especially in hilchos tefillin. One should
consult his rav for the appropriate atonement required of him. Some of
the cases discussed by the poskim include the following:
If one was not involved in the episode but merely observed as his
or another person’s tefillin fell to the ground.
If the tefillin fell to the ground while enclosed in a tefillin bag
or in their protective cases (boxes).
Some hold that one need not fast if the tefillin fell from a height of
less than three tefachim (approximately 10-12 inches).
Some poskim hold that fasting is required only if the tefillin fell due
to negligence but not if it was accidental.
If fasting will pose a hardship and make it difficult for one to
fulfill his duties, the following men may be lenient about fasting and give
charity instead: a physically weak person, a Torah scholar, a Torah teacher
or a communal activist (askan).
1. Chulin 89a.
2. O.C. 27:8; Mishnah Berurah 27:44.
3. Mishnah Berurah 27:44.
4. Mishnah Berurah 27:41.
5. According to the measurements of Chazon Ish. According to the
measurements of Rav A.C. Naeh, the l'chatchilah minimum is 10 millimeters;
See Shiurei Torah 3:37. If the retzuah shrinks to less than 9 millimeters
wide and no other tefillin are available, a rav should be consulted.
13. Rav M. Feinstein was asked: How much whiteness on the tefillin straps
renders them invalid? He is quoted (Guide to Practical Halachah, vol. 1, pg.
158) as answering: “For what is needed for the shiur, we are stringent—even
if a tiny drop is not black, the area must be repainted. Beyond that, the
amount does not matter unless it is really noticeable.” See also Zichron
Eliyahu (based on the rulings of Rav Y.S. Elyashiv) 20:7.
14. L'chatchilah, the l'shem mitzvas tefillin must be stated aloud; see
Mishnah Berurah 11:4; 32:24.
15. Beiur Halachah 33:4, s.v. pasul.
16. Mishnah Berurah 33:23.
17. Rav Y.S. Elyashiv and Rav C.P. Scheinberg, quoted in Mevakshei Torah,
vol. 4, pg. 415.
18. Mishnah Berurah 27:16.
19. Although Doveiv Meisharim 2:37 rules that one should remove his
wristwatch, he retracted that ruling in later years (Yechaveh Da’as 3:2).
20. Emes l’Yaakov, O.C. 27, note 31.
21. See Peri Megadim (Mishbetzos) 27:4; Teshuvos v’Hanhagos 2:26; Rav. C.
Kanievsky (Doleh u’Mashkeh, pg. 31).