QUESTION: The Gemara records a dispute with regard to whether wet twigs are Muktzah on Yom Tov. RASHI explains that the opinion that wet twigs are Muktzah is based on the principle that "Lo Nitnu Etzim Ela l'Hasakah" -- the exclusive purpose of wood on Yom Tov is fuel for a fire. A wet twig cannot be used as fuel for a fire is Muktzah, and thus it is Muktzah because it has no use at all now. The other opinion maintains that a wet twig still may be used for a very large fire, and therefore it is not Muktzah.
The Gemara implies that a twig fit for fuel may be moved for other purposes. Since it is fit for a fire, it may be used for any purpose. RASHI (DH b'Retiva, and as quoted by TOSFOS DH v'Hilchasa) says that this is true according to the opinion that "Lo Nitnu Etzim Ela l'Hasakah." That principle, however, states that twigs may be used only for a fire. Why is one permitted to use the twigs for other purposes?
ANSWER: RASHI does not mean that this opinion maintains "Lo Nitnu Etzim Ela l'Hasakah" in the literal sense. Rather, Rashi means that according to this opinion, since the main purpose of wood is for a fire, if it is not fit for its main purpose a person does not have in mind before Yom Tov to use it on Yom Tov. Thus, it is Muktzah and may not be used for any purpose. If it is fit for its main purpose, then it may be used for any purpose.
QUESTION: Rava rules that one may not use a piece of wood from a broken utensil as firewood on Yom Tov, since the wood was not prepared for such use before Yom Tov. The Gemara infers from here that Rava must follow the view of Rebbi Yehudah, who prohibits objects like this as Muktzah on Yom Tov. The Gemara questions this assumption from another statement of Rava. The Gemara relates that on Yom Tov, Rava told his servant to roast a goose and throw the intestines to a cat. The Gemara understands from this statement that Rava follows the view of Rebbi Shimon, who argues with Rebbi Yehudah and permits one to move an object on Yom Tov for the sake of animals, even though the object was designated for human use and not for animals before Yom Tov.
Rashi (DH Kivan d'Mesrechi) writes that the goose intestines were still fit for human consumption on Yom Tov.
How does Rava's ruling in that case imply that he follows the view of Rebbi Shimon? Perhaps Rava agrees with Rebbi Yehudah, who prohibits one from giving to animals an object designated for man only when the object is no longer fit to be used by man. (When the object is no longer fit for its original purpose of serving as food for man, it is considered Nolad and is Muktzah.) If, however, the object still can be used by a person (that is, it is fit for its designated use), even Rebbi Yehudah agrees that it is not Muktzah and it may be given to animals. Why, then, does the Gemara assert that Rava's ruling in the case of the goose intestines demonstrates that he rules like Rebbi Shimon? The goose intestines were still fit for human consumption!
The type of Muktzah which the Gemara here discusses is commonly referred to as "Muchan l'Adam Eino Muchan l'Behemah." This expression includes two distinct types of Muktzah: First, when the laws of Shabbos or Yom Tov prevent man from using an object (for example, on Shabbos a live animal is not fit for human use since the slaughter of an animal is forbidden on Shabbos), that object is considered Muktzah and may not be used for any purpose. Even though live animals are sometimes fed to dogs, since this animal is not fit for man at present it is Muktzah (even according to Rebbi Shimon) and may not be fed to dogs. (This is a form of Muktzah Machmas Isur.)
Second, when something happens to an object on Shabbos that renders it unfit for man, it may not be used for any purpose, not even as food for dogs (it is considered a form of Nolad). For example, if an animal was alive before Yom Tov (and was fit for man since he could slaughter and eat it on Yom Tov) and then it died on Yom Tov and became unfit for man, it remains Muktzah and may not be fed to dogs.
In Rava's case, the intestines of the goose fell into neither category. No law of Yom Tov prevents the intestines from being used by man, and nothing happened to the intestines to render them unfit for human use.
(a) RASHI (here and in Shabbos 142b) explains that the reason why goose intestines are not fit for man is not because any change occurred to them, but simply because it is not the normal manner to eat goose intestines on Yom Tov. Therefore, it is considered as though the laws of Yom Tov prohibit this item from human use (the first category of "Muchan l'Adam Eino Muchan l'Behemah" mentioned above), and that is why the intestines may not be given to animals according to Rebbi Yehudah.
(b) TOSFOS (here, DH v'Shadi, and in Shabbos 29a, DH Achlan) challenges Rashi's explanation from the Gemara in Shabbos (128a) which states that one is permitted to move raw meat on Shabbos because it is possible for people to eat the meat in such a state. It certainly is not the accepted practice to eat raw meat on Shabbos, and yet that fact does not render the meat Muktzah.
Tosfos therefore explains that goose intestines are edible as soon as the goose is slaughtered (before Yom Tov); however, shortly afterwards (on Yom Tov) the intestines spoil and become inedible. Since the intestines are no longer fit for man, they become Muktzah according to Rebbi Yehudah. (Tosfos understands that they fall into the second category of Muktzah mentioned above, Muktzah prohibited because of Nolad.)
Perhaps Rashi maintains that goose intestines are not comparable to raw meat for the following reason. Rava slaughtered the goose because he intended to eat its meat, and the intestines are secondary to the meat. Relative to the meat, the intestines are not fit for use on Yom Tov. Raw meat, in contrast, is not secondary to anything else, and therefore it is not Muktzah. (M. Kornfeld)