Chullin Daf 61 צולין דַף 61

The Mishnah on Daf 59a taught that the signs of kosher birds were not taught by the Torah. The Gemara objects that a Baraisa states that the נשר is recorded as a nonkosher bird, and we derive from it: מה נשר מיוחד – just as the נשר is distinct, שאין לו אצבע יתרה – that it does not have an added toe, וזפק – nor a crop, ואין קורקבנו נקלף – and its gizzard cannot be peeled, ודורס ואוכל – and it claws and eats, and is not kosher, so too all birds which parallels a נשר with all these features are not kosher. On the other hand, the Torah taught that תורין are kosher, and we derive from them that just as תורין do have an added toe, and a crop, and a gizzard which can be peeled, and it does not claw and eat, and is kosher, so too all birds sharing these features are kosher (these two derivations appear contradictory, and this is addressed by the Gemara). This Baraisa seemingly proves that the סימנים of kosher birds are derived Biblically!? Abaye answers: לא נאמר פירושן מדברי תורה – the clarification of the סימנים is not stated in the Torah, אלא מדברי סופרים – rather, it was taught by the Sages.

Rebbe Chiya taught a Baraisa: עוף הבא בסימן אחד טהור – a bird which comes before us with a single sign of kosher birds is kosher, לפי שאין דומה לנשר – because it is not similar to the נשר. נשר דלית ליה כלל הוא דלא תיכול – Only a נשר, which has no kosher signs at all, you may not eat, הא איכא דאית ליה חד תיכול – but any bird which has even one kosher sign, you may eat. The Gemara explains that we cannot derive from the twenty birds with three kosher סימנים, which the Torah taught are not kosher, that all birds with even three kosher סימנים are not kosher, because then it would be unnecessary for the Torah to prohibit the עורב, which has only two kosher סימנים. We cannot derive from the עורב to prohibit any bird with two סימנים, because then it would be unnecessary to prohibit the פרס and עזניה, which have only one סימן each. We do not derive from them to prohibit any bird with one סימן, because then it would be unnecessary to prohibit the נשר, which has no סימנים. The Torah’s prohibition of נשר proves that a single kosher sign is sufficient in birds.

Having concluded that any bird with a single kosher sign is kosher, the Gemara asks: אלא תורין דכתב רחמנא למה לי – why, then, did the Torah write that תורין (which have all four kosher signs) are kosher birds, since they do not serve as a model for other kosher birds? Rav Ukva bar Chama answers: לקרבן – they are specified to teach that only they, and young pigeons which are mentioned with them, are valid as a korban, and no other kosher birds.