By Rabbi Shmuel Wise

Real Clear Daf

BANNER: Clear Daf

A review of some of this week’s daf yomi key concepts (Parashas Mishpatim – Chullin)

Question: Are the kosher-signs just signs or are they reasons?

Answer: Rav Elchanan Wasserman in his Kovetz Shiurim (Chullin; letter 27) engages with this question as it pertains to the Gemara’s discussion of Monday’s daf this week (Chullin 62b). R’ Pappa there rules that the “swamp-rooster” is among the non-kosher birds, but the “swamp-hen” is among the kosher birds. A trick to remember this, R’ Pappa offers, is to recall the halachah that a male Ammonite convert is prohibited from marrying into the congregation, but a female Ammonite convert is permitted.

At first glance it would appear that these two “swamp” birds are of the same species but, somehow, the male version of this species is on the non-kosher list and the female version goes on the kosher list. Tosfos here, however, rejects such a reading, pointing out that if they are of the same species, then by definition the “swamp-rooster” was born of the “swamp-hen” — a kosher bird — and since “anything that comes from something permitted is itself permitted,” the “swamp-rooster” should also be permitted. Rather, Tosfos explains, these two birds are of two different species — one kosher, the other not.

Tosfos in Niddah (50b), however, explains differently. Tosfos there suggests that the “swamp-rooster” and the “swamp-hen” are indeed of the same species. Yet the “swamp-rooster” specifically is not kosher because it lacks the kosher-signs of birds delineated in the Mishnah on 59a. As to the rule which says that “what came from something kosher is itself kosher,” Tosfos there explains that the rule doesn’t apply to a creature that develops in an egg outside of the mother’s body (see there for further elaboration on this).

Tosfos in Niddah seems to make the astounding suggestion that the kosher-signs we are learning about in these pages are not simply ways to refer to the species that are kosher but are themselves what make the animals kosher! Indeed, Rav Elchanan understands that this is the very point of contention between Tosfos here in Chullin and Tosfos there in Niddah. Tosfos here contends that the kosher-signs are nothing more than signs that point to certain species that are kosher. Thus, it is untenable that there would be a species with a non-kosher male version and kosher female version; it’s either a kosher species or a non-kosher species. Tosfos in Niddah, on the other hand, understands that everything is about the signs: With the signs, the individual animal in question is kosher; without them, it is not. Hence, it’s entirely plausible to have a kosher and non-kosher animal within the same species.

The notion that the presence of the kosher-signs is what makes an animal kosher seems hard to reconcile with the plain understanding of the laws of the kosher animals. If everything revolved around the kosher-signs, there should be no need for the Torah to mention any particular species. Why then does the Torah do so by the kosher animals and birds? In fact, when it comes to the kosher birds, the Torah doesn’t even mention the kosher-signs whatsoever and instead just lists the non-kosher birds! Evidently, the Torah did in fact prohibit entire groups (species) of animals, and the kosher-signs are merely a means of describing the groups of animals that are prohibited.

But what of the words of Tosfos in Niddah? Didn’t Tosfos there state regarding the swamp bird that only the male, which lacks the kosher-signs, is not kosher?

It could be suggested that Tosfos himself is struggling with this very issue when he raises the point that “what is born of something kosher is itself kosher.” Tosfos deals with this problem by suggesting that the “swamp-rooster” is not technically born of its mother (see above). Thus, Tosfos is arguing that in light of the facts that (a) the “rooster hen” has different physical attributes than its female counterpart (that does not display the kosher signs), and (b) it isn’t legally born of its mother, the halachah views it as a different species with respect to its kosher-ness. This would mean that Tosfos in Niddah agrees that the kosher-signs merely refer us to certain groups of kosher animals.

Rabbi Wise is maggid shiur of Real Clear Daf, a website and mobile app that offers free audio shiurim and other resources to assist your journey through Shas. He is also the director of Tehillim Together, a mobile app (for iOS and Android) that offers a translated sefer Tehillim and facilitates Tehillim groups. To be a sponsor or to reach Rabbi Wise, please write to or call 855-ASK-RCD-1 (275-7231).


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