If one looks into the Tur and Beis Yosef at the beginning of Hilchos Chol HaMoed in Simana 630 you will find a big maklokes rishonim if malacha on Chol HaMoed is an issur d'oraisa, d'rabbanan, or perhaps is d'oraisa however was given over to the Rabbis to determine what is ossur to do and what is muter to do on Chol HaMoed.
Someone wanted to bring a proof from a Mishnah in Chagigah that malacha on Chol HaMoed is only an d'rabbanan. It says in the Mishnah (Perek 1 Mishnah 8):
Heter Nedarim Porchin b'Avir...
In regards to the first statement that "Heter Nedarim" are "porchim b'avir" Rashi says that the ability of a Chacham to be matir a neder has a remez in the Torah, however doesn't have anything to be "somach" on from the Torah (to say that it's m'doraisa. However there is a remez and the whole halacha was given over to the Chachamim in the Torah Shel b'Peh. This is a similar idea of what some Rishonim hold about Chol HaMoed that it is from the Torah however was given over to the Chachamim to decide what is muter or ossur. The person wanted to say that you see since the Mishnah didn't give hilchos Chol HaMoed as an example (pointing out that Mesectas Chagigah is in Seder Moed and would have been more fitting to give an example that is relavant to Seder Moed>) must be that the issue of issur malacha on Chol HaMoed is in fact only a d'rabbanan. As well that it's not included in the last group of halachos that are listed which do have a "smach" in the Torah. Since it's not in the
first and not in the last, must be only d'rabbanan altogether.
My question is as follows:
This also idea seems rather difficult to me. Is it possible to bring such a proof from the Mishnah in such a way (specifically this idea and this Mishnah.) Is this way of learning from a Mishnah have any source or foundation?
Yehoshua, Yerushalayim, Eretz Yisrael
Dear Yehoshua,
It seems like a logical argument. Isn't that enough of a foundation? The question, though, is whether the concept of "Heter Nedarim Porchin b'Avir" is equivalent to the concept of "Lo Masrah Torah Ela l'Chachamim" by Chol haMoed. By Chol haMoed we are positing that the Torah in a sense "wrote a blank check" to the Chachamim and left it up to their Chachmah to decide which Melachos to forbid and which to permit. By Hataras Nedarim we are positing simply that it is a d'Oraysa Din that has almost no mention in the Torah sh'b'Ksav. That seems to be the theme of the whole Mishnah: things which are d'Oraysa but have varying degrees of Remez in Torah sh'b'Ksav - Hataras Nedarim has almost none and Shabbos has a bit more.
b'Yedidus,
Yonasan Sigler
This is not a Psak Halachah