The prohibition of bal tosif seems simple enough, yet its various complications led the Sefer haHinukh (mitsvah 454) to note that his summary was "the generalities of this prohibition that my teachers...lifted out of the words of the Talmud after great toil." Many of those complications involve the attempt to define how adding to a mitsvah would be considered a violation of bal tosif. Consider, for example, someone who sits in a sukkah the day after Sukkot. While that might seem to be a clear case of adding on to the Torah, many authorities point out that such a person would only transgress bal tosif if he or she specifically intended the act to constitue a performance of the mitsvah; otherwise, the act of sitting in that structure might have no halakhic significance.

A whole different set of issues is raised by the notion of ritual and halakhic creativity, where a person or group of people wishes to add a new mitsvah to the Torah. Here it might seem simpler to violate bal tosif, since it is easier to identify the new element as additional. To use Ramban’s example (from his commentary on the Torah to Devarim 4;2), if a person were to make up a new holiday— as Yerov`am did in Melahim I, 12:32-33— that’s bal tosif. This aspect of bal tosif raises several issues for Centrist Orthodoxy, since we have certainly added days to the Jewish calendar, most prominently Yom haShoah, Yom haAtsmaut, and Yom Yerushalayim.

Before getting to that issue, however, we need to consider a more general question that arises in the context of this aspect of bal tosif, the power of Hazal to legislate. Aside from the holidays of Hanukkah and Purim (which relate to Ramban’s assumptions about bal tosif), Hazal made many rules for the Jewish people, all of which might be seen as prohibited additions to the Torah. Why is it that we do not conceive of Hazal as violating bal tosif in these areas?

One interesting answer is that of Rashba (in his commentary to Rosh Hashana 16b), who simply distinguishes between a single individual and Hazal. The issur of bal tosif, he says, applies to an individual who makes up a new mitsvah. If someone is listening to a rabbinic body in performing a Jewish act, however, that cannot be considered bal tosif. Rashba does not, however, fully define who qualifies as a sufficient body to make such legislation and not have it be considered bal tosif, vital information if we were to adopt his position.

A more prominent answer is provided by Rambam in Hilkhot Mamrim2:9, where he distinguishes between Hazal saying something on their own authority and their claiming that some rule is ordained by the Torah. Using the example of basar be-halav (milk and meat), Rambam points out that it would be prohibited for Hazal to announce that the Torah prohibits mixing the flesh of poultry with milk, since it does not, but that it is permissible for them to prohibit that combination on their own authority, as a way of protecting us from violating Torah laws. Indeed, Rambam and most rishonim see that as one of Hazal’s prime functions. It is not the fact of adding that is a problem, it is only pretending that the Torah itself made this commandment.

Notably, Rabad disagrees, pointing out that reasonably often Hazal provide a verse in Scripture as the source of some rule, and it is only later rabbis who pointed out that the verse is an asmakhta rather than the actual source. An asmakhta, let us recall, is a Rabbinic use of a verse that is not meant to provide actual legal content. The asmakhta might serve simply to help remember an issue, or, as others have suggested, it might be a way of showing that Scripture incorporates a certain value, even if not explicitly enough to deem that notion as obligatory at the Torah level. Rabad assumes that the rabbi who cited a verse for a certain law was not clear with the members of his own generation that it was, indeed, only an asmakhta. If so, it would disprove Rambam’s contention, since the gemara is full of cases where rabbis made rules that were apparently of Torah origin, and only later generations revealed that they were rabbinic, with the verses "only" serving as asmakhta.

Rambam could simply deny Rabad’s assumption, countering that originally everyone understood that the verse was an asmakhta. In later times, confusion arose as to the relationship between the verse and the rule that needed to be cleared up. Rambam’s view, we should note, requires that we maintain a diligent awareness of the source, and differing levels of obligation, for our various Jewish practices. While we need to observe all authoritative Jewish practices (and simple customs would again differ from Rabbinic rules), we also need to keep differences in the sources of those practices firmly in mind. What is Torah-ordained is more divine, more sacred, and more essential to being a Jew than that which Hazal instituted to protect or further the goals of the original system.

That does not minimize our obligation to follow Hazal carefully, at least because the Torah requires us to, in the mitsvah of lo tasur. At the same time, Rambam reminds us that we must maintain our awareness that these rules are not as essential to the divine plan for Jewish life as the Torah’s rules; had human history gone differently, perhaps Hazal would not have felt the need to institute some of these rules. Otherwise, we run the risk of violating bal tosif, a Torah-ordained prohibition. Be-`ezrat Hashem, next week we will consider the implications of Ramban’s view, and its ramifications for the "new"holidays we have in our time. Shabbat Shalom.