Tuesday, October 11, 2011

when an issur derabbanan negates a kiyum d'oraysa

We once discussed (link) the chiddush of the Pri Megadim that when Chazal qualify how a mitzvah d'oraysa should be performed, the failure to meet the derabbanan criteria negates even the kiyum d'oraysa of that mitzvah. For example, there is a din derabbanan that one cannot sit in a sukkah and eat off a table that remains inside one's house. Even though this qualification was instituted by the derabbanan and has nothing to do with the din d'orasya of sukkah, Tos (Sukkah 3) holds that failing to fulfill the din derabbanan negates the kiyum d'oraysa of yeshivas sukkah.

At first glance this chiddush seems to be a machlokes Tana'im later in the masechta. R' Meir allows a sukkah to be made on top of an animal; R' Yehudah does not. The gemara (23a) explains that we learn from the pasuk, "Ba'sukkos teishvu shivas yamim," that a sukkah must be usable for the entire seven day duration of the chag. R' Yehudah holds that since one is not allowed to climb on an animal on Shabbos and Yom Tov, a sukkah built on top of an animal is not usable for seven days. R' Meir counters that the prohibition of climbing on an animal is only a din derabbanan; you can't say a sukkah does not meet the d'oraysa criteria of being usable for seven days just because of a derabbanan disqualification. Apparently, R' Yehudah holds othewise -- the din derabbanan that prevents one from using a sukkah built on an animal does in fact negate the d'oraysa kiyum of sukkah, exactly like the chiddush of the Pri Megadim.

Yet maybe things are not so simple and one can be mechaleik. The requirement of having a table within the sukkah is a din in hilchos sukkah. Perhaps in principle even R' Meir agrees that failing to meet a derabbanan criteria of hilchos sukkah can negate the kiyum d'oraysa of sukkah. However, the prohibition of climbing on an animal is a general din in hilchos Yom Tov. R' Meir perhaps holds that a din derabbanan of hilchos Yom Tov cannot negate a kiyum d'oraysa of sukkah.

R' Akiva Eiger writes that even though Chazal disallowed blowing shofar on Shabbos lest one come to carry the shofar, if one went ahead and blew, one fulfills the mitzvah d'oraysa of shofar, albeit at the expense of an issur derabbanan. Against the Pri Megadim? Again, maybe not. The issur of carrying is a general din in hilchos Yom Tov, not a din in hilchos shofar. A violation of a din in hilchos Yom Tov does not have the power to negate a kiyum d'oraysa of shofar or sukkah.

6 comments:

  1. Would this include someone who blesses the RBSO after eating or praying something other than the Amidah chazal coined aren't yotz'im deOraisa either?

    (If we were to hold that way, it would eliminate any problems singing Tzur Mishelo Akhalnu.)

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  2. I mentioned that same point here:
    http://divreichaim.blogspot.com/2010/06/when-zemer-fulfills-mitzvah-doraysa.html

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  3. Still, one wouldn't need to invoke mitzvos tzerikhos kavanah. (I don't think I would have emphasized the deOraisa angle to say it applies, I would have gone more with avodah shebeleiv.)

    In any case, this argument, that once there is a din derabbanan, even the deoraisa isn't fulfilled, would work there too.

    If you want to get really blurry / broad, you could relate this conversation to bitul chameitz on erev Pesach. There too a derabannan creates a reality that changes the application of the de'oraisa. Perhaps there is a general topic of rabbanan making a chalos that is then part of the metzi'us about which we have to apply the de'oraisa?

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  4. "Yet maybe things are not so simple and one can be mechaleik. The requirement of having a table within the sukkah is a din in hilchos sukkah... However, the prohibition of climbing on an animal is a general din in hilchos Yom Tov."

    This is a nice chiluk. Perhaps we can also be mechalek in the opposite direction, however. The requirement of "sukka re'uyah l'shiva" per R. Yehuda may mean that the sukka must actually be re'uyah to use in your present circumstances, and if you can't enter it for whatever reason then it isn't re'uyah. So once the rabanan forbade entering a sukka in a tree etc. on yom tov or shabbat, such a sukka is no longer re'uyah l'shiva in practice -- and I think Rashi on "ha-re'uyah l'shiva" on sounds like that. Whereas R. Yehuda need not necessarily hold that rabbinic requirements in hilchos sukka generally become mandatory even for d'oraysa level of fulfillment, as Tosafos 3a and Pri Megadim suggest (a much bigger chidush, in my very humble opinion).

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  5. Steven,

    The question would then be whether re'uyah includes a lack of issurim. I'll explain why I'm unsure.

    It's another analogy.

    If you're wearing a beged with tzitzis that you're not sure require tzitzis, you can't wear it in a reshus harabbim on Shabbos. Without the mitzvah, the tzitzis aren't beteilos to the beged, so it's hotza'ah. However, you have to put tassles on the beged mishum safeiq or else you can't wear it. So why doesn't that need make them beteilos to the beged? Why do we demand the chiyuv itself? Why is this any worse than wanting decorative buttons?

    Perhaps just as mishum safeiq is not enough to make the tzitis intrinsic to the beged in the mind of the wearer, an issur derabbanan isn't enough to make the sukkah "einah re'uyah leisheiv bah" on a de'oraisa level. We divorced levels of duty in once case, how do we know we don't do so in both?

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  6. >>>So once the rabanan forbade entering a sukka in a tree etc. on yom tov or shabbat, such a sukka is no longer re'uyah l'shiva in practice

    You are forced to take the PMG's position, or how else can you explain looking at things through a d'orasya lens only why a sukkah built on an animal is not usable? The Torah certainly has no practical impediment to its use.

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