The question of how left-handedness affects one’s halakhic status perhaps primarily concerns those who are left-handed (and their close relatives), but it sheds interesting light on several topics for all concerned about them. I thought, therefore, to take a sheet and dedicate it to the question of left-handedness.

The most famous issue where the question arises is in terms of tefillin, where there is general agreement that a left-handed person places the tefillin on his right hand (which, for him, is the weaker hand, called in the halakhic literature semol dideh, left for him). For an ambidextrous person, however, the left hand is preferred, since that would have him conform to the rest of the world.

The question raised in this context is how we judge whether a person is left handed or not, since there are situations where a person performs certain functions with the right hand and certain with the left. The case the Shulhan Arukh (Orah Hayyim 27;6) knows is that of a person who writes with his right hand and does everything else with the left. The easiest way for this situation to have come about is that his parents "switched" him when young, perhaps in accord with the long-standing leeriness of left-handed people. The Shulhan Arukh records approvingly the opinion that we follow the way the person writes, while the Bah believed that we would follow that person’s general tendencies (this can get hard to determine— what is a person who throws right-handed, but bats left-handed and writes left-handed?). Magen Avraham, although generally sympathetic to the Shulhan Arukh’s opinion, adds that in cases where the person was "switched," meaning that he was forced to learn an unnatural way of writing, we would ignore that and follow his general tendencies.

I mention this halakhah because of the importance it attaches to how we write. In some sense—and I do not intend to define that sense here, but note it for further consideration—writing seems to be a fundamental activity that humans do with their hands. After all, if a person picks up objects, eats, and plays with his left hand, our relying nonetheless on his writing hand as the definitive factor in characterizing him is highly suggestive.

The halakhah that an ambidextrous person should act as if he were right-handed is echoed in the laws of tefillin, since there too the right hand is preferred. Similarly, Rambam cites left-handedness as a mum, a physical defect for priests who wish to serve in the Temple (the whole concept of mumin, of what are considered physical defects, is a topic that deserves further discussion, but rarely comes up in halakhic contexts). Interestingly, while we see writing with the right hand as preferable even for an ambidextrous person (for such occasions as writing tefillin or a get), such a person would be liable for writing with either hand on Shabbat (despite the halakhah that one can only be liable for writing in a usual manner). We apparently distinguish between situations where the question is whether one wrote in an ordinary manner for oneself (the Shabbat question) and where we seek some objectively ordinary writing. In the latter case, the ambidextrous person should use the right hand.

Another situation where halakhah recognizes the differences between a left-handed person and an ordinary person is in the holding of a kos shel berakhah, a cup of wine used to give special sanctity to certain blessings (such as saying Birkat haMazon with a cup of wine, under a huppah, havdalah, and so on). In that case, there are several halakhot which are simply ways of beautifying the occasion, not strict rules; one is that a left-handed person use his left hand to hold the cup.

Two other halakhot are only questionably related to a person’s left-handedness. In the case of lulav, for example, right-handed people are supposed to hold the lulav in their right hand, and the etrog in their left (See Orah Hayyim 651), a rule the Shulhan Arukh applies to left-handed people as well. According to him, apparently, the holding of a lulav in the right hand is not because it is the stronger hand, but for some other (unnamed) reason. Similarly, the placement of the mezuzah is on the right, regardless of the owner’s status. As Shakh points out (Yoreh Deah 289, on section 3), the mezuzah is a function of the house, not of the person who owns it (or even the people who live there and visit there—even if all those people were left-handed, the mezuzah still goes on the right). That would be chalked up to a general tilt to the right in halakhah, not a function of the tendencies of the people involved. We should point out, however, that in the case of lulav, Rema disagrees, and holds that a left-handed person carries the lulav in the left hand, putting it back into the realm of that person’s favorite hand, not some objective right-left issue.

For most cases, then, the question of left-right is really a question of personal abilities, so that left-handers will do things differently from right-handers. In some situations, however, left-handedness is a flaw, or at best is ignored, with the halakhah favoring the right side. Shabbat Shalom.