Placement of Tefillin on the Weaker Arm

One of the well-known laws of tefillin is that a right-handed individual places his tefillah shel yad on his left arm and a left-handed individual places it on his right arm.  In this issue, we will explore discuss the rationale for this law, its parameters and the practical applications of this discussion.

The Three Opinions in the Talmud

The Gemara, Menachot 36b-37a, cites three opinions regarding the proper arm to place tefillin.  The first opinion is that when the Torah states to place tefillin on one's arm, it implies that one should place it on one's left arm.  The second opinion is that the Torah implies that one ties (places) the tefillin with the same arm that one uses to write tefillin.  Since, one must write tefillin with one's right hand, one must tie the tefillin with one's right arm and in order to do so, one must place it on one's left arm.  The third opinion is that the Torah implies that one places tefillin on one's weaker arm.

R. Ya'akov ben Asher (1269-1343), Tur, Orach Chaim no. 27, and Even HaEzer no. 169, rules in accordance with the first opinion that there is an inherent requirement to place tefillin on one's left arm.  Tur adds that a left-handed individual places it on his right arm because his "left hand" is on the right.  Tur takes the approach that a left-handed individual is viewed as the reverse of a right-handed individual and therefore, his halachic right arm (and right leg for the purpose of chalitzah) is situated on the left side of his body.  Rambam (1135-1204), Hilchot Tefillin 4:2-3, also rules that one must place tefillin on one's left arm and that a left-handed individual's right arm is considered the "left arm" for these purposes.

Rabbeinu Peretz (d. 1295), in his Hagahot L'Sefer Mitzvot Katan (Mitzvah 153, note 8) quotes Rabbeinu Yechiel that a left-handed individual who writes with his right hand should place tefillin on his left arm because one must tie the tefillin with the same hand one writes with.  Since this individual writes with his right hand, he must tie the tefillin with his right hand and this can only be accomplished by placing the tefillin on one's left arm.  Rabbeinu Yechiel clearly follows the second opinion.

Rabbeinu Nissim (1320-1380), Chullin 30a, s.v. U'Makshu, presents the question of whether a left-handed individual is viewed as the reverse of a right-handed individual.  However, he notes that this question is irrelevant to tefillin because one places tefillin on one's weaker arm.  Rabbeinu Nissim clearly follows the third opinion that the weak arm is the determinant.

The Role of Writing

There are a number of reasons why the hand that one writes with should be considered a determinant.  First, as we mentioned earlier, according to Rabbeinu Yechiel (as presented by Rabbeinu Peretz), the hand that one writes with is a direct determinant.  One places tefillin on the opposite arm of one's writing hand.  This applies even if someone performs all other activities with the hand that is opposite of his writing hand.

Second, Tosafot, Menachot 37a, s.v. Ma, discuss the case of someone who writes with his right hand but performs all other activities with his left hand.  They imply that such an individual is comparable to an ambidextrous individual (someone who can use both hands).  The Gemara, Menachot 37a, states that an ambidextrous individual places tefillin on his left arm.

Third, R. Yoel Sirkes (1561-1640), Bach, Orach Chaim no. 27, suggests that R. Yechiel's opinion is that one only places tefillin on his right arm if his left hand is used for all activities including writing.  He explains that writing is only a determinant in a left-handed individual.  If a right-handed individual writes with his left hand or a left-handed individual writes with his right hand, he places tefillin on his left arm.  [R. Moshe Feinstein (1895-1986), Igrot Moshe, Orach Chaim 4:11, notes that while in reality, the opinion of Tosafot and R. Sirkes' opinion will yield the same conclusion, the two opinions are based on different analyses.  According to Tosafot, writing is considered an extremely significant activity in determining whether someone is right-handed or left-handed.  Therefore, one who performs all of his activities with one hand and writes with the other may be compared to someone who is ambidextrous.  According to R. Sirkes, one only places tefillin on his right arm if he satisfies the second opinion - that he writes with his left hand - and the third opinion - that his left hand is the weaker hand.]

As a matter of practical Halacha, there are a number of opinions regarding one who writes with one hand and performs all other activities with the other.  R. Yosef Karo (1488-1575), Shulchan Aruch, Orach Chaim 27:6, quotes two opinions on the matter.  The first opinion is that the determining factor is the majority of one's activities, even if one writes with the opposite hand.  The second opinion is that writing is the determining factor.  Rama (1520-1572), ad loc., seems to rule in accordance with the second opinion.  The Vilna Gaon (1720-1797), ad loc., rules in accordance with the first opinion.  As noted earlier, R. Sirkes rules that one only places tefillin on one's right arm if he is left-handed and writes with his left hand.

Later authorities also dispute what one should do in this situation.  R. Yisrael M. Kagan (1838-1933), Mishna Berurah, Bei'ur Halacha 27:6, s.v. V'Hachi, seems to side with the opinion that writing is the primary determinant.  He adds that in most cases, one can still satisfy the opinion that writing is not the determinant.  This assertion is based on his suggestion that if the individual can perform most activities with his weaker hand, but not as well, the fact that he uses the weaker hand for writing would render him ambidextrous.  Therefore, he would place tefillin on his left arm.  R. Yechiel M. Epstein (1829-1908), Aruch HaShulchan, Orach Chaim 27:16, codifies the opinion of the Vilna Gaon that writing is not a determinant.  R. Moshe Feinstein, op. cit., rules that if one writes with his weaker hand, he is considered ambidextrous and places the tefillin on his left arm.

One Who Trained Himself to Use the Opposite Hand

Until recently, it was common for parents and teachers of naturally born left-handers to discourage use of the left hand as the primary hand.  Mordechai (1250-1298), Menachot 37b, cites two opinions regarding one who trained himself to use the opposite hand.  One opinion is that one follows his original orientation and the other opinion is that one follows his new orientation.

R. Yechezkel Landa (1713-1793), Dagul MeRivava to Magen Avraham 27:9, notes that the question regarding someone who trained himself to use the opposite hand only applies to one who trained himself willingly.  However, if one suffered a condition that didn't allow him to use his right arm and he eventually became left-handed, he is certainly considered left-handed.

Mishna Berurah, Bei'ur Halacha 27:6, s.v. V'Iter, notes that this discussion is relevant to an amputee whose strong arm was amputated.  The arm that remains is now the stronger arm and will be used for all activities.  As such, he is obligated to place the tefillin on what remains of the amputated arm (see Mishna Berurah 27:6).  R. Shlomo Zalman Auerbach (1910-1995), Minchat Shlomo 2:4, questions Mishna Berurah's application to an amputee.  He suggests that R. Landa's ruling is limited to someone who suffered paralysis or weakening of the arm.  However, an amputee who retains the strength of his arm but lacks the dexterity is still subject to the dispute cited by Mordechai.