On 3b, the gemara says beshlama according to rabba that a beitzah which is safek noldah on yomtov is assur, because he holds it's a safek d'oraisa. The Maharsha explains that rabba holds this is referring to a case of yomtov following shabbos, in which case it would be deoraisa if born on yomtov. But on 4a, rav and r yochanan have a machlokes about an egg being laid on shabbos, if its mutar on the next day of yomtov, and rav assurs it, and the gemara says they're arguing about hachana derabba. So we see that in our case of safek when it was born, and its referring to yomtov after shabbos according to the maharsha, then mima nafshach its assur, whether its born today on yomtov, or whether it was born yesterday on shabbos, in both cases it would be assur becasue of hachana derabba. If so, why does the gemara say its assur becasue of safek deoraisa lechumra? Lechora this has nothing to do with that, there is no safek, mima nafshach its for sure assur.
Yaron Barach, Brooklyn, NY
Yaron, your questions in the past have always been penetrating, and this one is no exception!
1. I think we must say that there is a third possiblity: The egg might have been laid on Friday. If that was the case, then it would be totally Mutar.
2. If we say that there exists this third possibility, we might gain something else. Rashi (DH u'Sfeika) writes that the Gemara at this stage assumes that there is a Safek whether the egg was born on Yom Tov or on a weekday. This assumption changes only when the Gemara says that according to Rav Yosef and Rav Yitzchak, the egg is Safek Tereifah and the Safek has nothing to do with Yom Tov.
However, according to Rabah there is no reason to say that the Gemara changes its understanding. How, then, can the Maharsha say that according to Rabah, the Gemara is refering to a case of Yom Tov after Shabbos? This is contradicted by the words of Rashi, because what Rashi wrote -- that the egg might have been born on a weekday -- remains valid according to Rabah! How can the Maharsha say that the case is when Yom Tov is on a Sunday and no weekday is involved?
3. However, if we say that even according to the Maharsha the egg might have been laid on Friday, then everything fits into place: because Yom Tov is on Sunday, an Isur d'Oraisa might be involved, but because the egg might have been born on Friday, there is a Safek involved, which is why the Gemara says Sfeika d'Oraisa l'Chumra.
(4. However, I found that the Sefer Simchas Yom Tov, by the Maharal Tzintz, apparently does not agree with the above reasoning. He writes that if the egg might have been laid on Friday, then one should permit everything based on a Sfek Sfeika: perhaps the egg was laid on a weekday and is totally permitted, and even if it was not laid on a weekday, it still may have been laid only on Shabbos and is Asur only mid'Rabanan. He writes that this type of Sfek Sfeika (i.e. where only one of the possibilities (that it was laid on Yom Tov) would make it Asur mid'Oraisa, and the other two possibilites are that it is only Asur mid'Rabanan or is totally permitted) is permitted entirely. I do not yet understand the reasoning of the Sefer Simchas Yom Tov, so for the moment I am going to stay with my answer: since the egg might have been laid on Friday, it is not definitely Asur with a "Mi'mah Nafshach" reasoning.)
Kol Tuv,
Dovid Bloom
1. I looked again at what the Simchas Yom Tov writes, and it seems that we m,ay remain with our original answer -- that since the egg that may have been laid on Yom Tov on Sunday may also have been laid either the day before (on Shabbos) or on Friday, this is still considered a Safek, because if it was really laid on Friday it would be totally permitted.
2. The principle in the laws of Sfek Sfeika that the Simchas Yom Tov cites, and that I mentioned in my first reply, may be illustrated by the following example. Rebbi Akiva Eiger (Teshuvos, end of 1:25) discusses the Halachah in the case of a woman who ate enough bread to be fully satiated by her meal and is now in doubt about whether she recited Birkas ha'Mazon. Rebbi Akiva Eiger writes that it seems that in such a case a Sfek Sfeika should exempt her from reciting Birkas ha'Mazon again out of doubt. The first Safek is the doubt about whether a woman is obligated mid'Oraisa to recite Birkas ha'Mazon. The second doubt is that perhaps in this case she did recite Birkas ha'Mazon. Rebbi Akiva Eiger writes that although all opinions agree that she is obligated to recite Birkas ha'Mazon at least mid'Rabanan, this fact does not diminish the first of the two Sfeikos mentioned above. Even though she is certainly obligated mid'Rabanan in Birkas ha'Mazon, the second Safek -- that perhaps she indeed recited it -- now becomes one Safek in a Halachah d'Rabanan, and the rule is that Safek d'Rabanan l'Hakel (in the case of a Safek d'Rabanan, one acts leniently).
This is similar to the Sfek Sfeika suggested by the Gemara here: (a) perhaps the egg was born on Friday and is totally permitted; (b) even if it was not born on a weekday, perhaps it was born on the Shabbos before the Sunday Yom Tov and is prohibited only mid'Rabanan. Although, according to the second possibility, it still would be prohibited mid'Rabanan, we still may apply the rule that one acts leniently in the case of a Safek d'Rabanan and the egg should be totally permitted. Why, then, does the Gemara say that the Safek is forbidden? This is the challenge of the Sefer Simchas Yom Tov (that I mentioned in my previous answer) to the suggestion that the egg might have been laid on Friday.
3. However, the conclusion of the Simchas Yom Tov is that in reality the above is not considered a Sfek Sfeika. This is because there in fact is only one Safek involved here, namely: was the egg laid on a weekday or not? In practice it does not matter whether the egg was born on Yom Tov or on Shabbos, but only whether it was born on a weekday or not. Accordingly, there is only one Safek, and this is why the Gemara states that it is forbidden because of Safek d'Oraisa l'Chumra.
Kol Tuv,
Dovid Bloom