• Various opinions of simanim for birds (ex., catching and eating prey in midair)

The Mishnah on Daf 59a listed the signs of kosher birds, and a Baraisa discusses them further. Rabban Gamliel says that a bird which claws and eats is definitely not kosher. If it does not claw, and also has an additional toe, has a crop, and its gizzard can be peeled, it is definitely kosher. Rebbe Elazar bar Rebbe Tzadok says we stretch out a cord to see how it perches: if it parts its feet with two toes in front and two in back, it is not kosher. But if it places three toes on one side and one on the other, it is kosher. Rebbe Shimon ben Elazar says: כל עוף הקולט מן האויר – any bird which seizes prey from midair is not kosher. Since the "ציפרתא", a kosher bird, also seizes prey in midair, Abaye clarifies: קולט ואוכל – it seizes and eats its prey in midair. “Others” say: שכן עם טמאים טמא – [A bird] which dwells with nonkosher [birds] is not kosher, and one which dwells with kosher birds is kosher. This seems to follow Rebbe Eliezer, who said that the reason the זרזיר went to the עורב is because it is its kind (i.e., nonkosher). However, the Gemara concludes that שכן ונדמה – if it dwells with and resembles a nonkosher bird, the Rabbonon agree it is not kosher.

• A kosher grasshopper’s wings must cover "רובו"

The Mishnah on Daf 59a listed the kosher signs of grasshoppers: כל שיש לו ארבע רגלים – any kind which has four walking legs, וארבע כנפים – four wings, וקרצולים – and jumping legs, וכנפיו חופין את רובו – and its wings cover most of it, is kosher. [Rebbe Yose adds that its name must be "חגב".] In defining wings covering “רובו,” Rav Yehudah said in the name of Rav: רוב ארכו – the wings must cover most of [the grasshopper’s] length. Some quote Rav’s opinion as רוב הקיפו – most of [the grasshopper’s] circumference. Because of these two definitions, Rav Pappa said: הלכך בעינן רוב ארכו ובעינן רוב הקיפו – therefore, we require the wings to cover most of its length and most of its circumference.

• Two methods of darshening the list of four kosher grasshoppers in the Torah (ראשו ארוך)

The Torah mentions four species of kosher grasshoppers in the Torah: ארבה, סלעם, חרגל, and חגב, and the term "למינו" or "לימנהו" – according to its kind is written after each type. Two Baraisos darshen these words. The first Baraisa, from Toras Kohanim, includes another four types of grasshoppers, each of which shares the physical characteristics of one of the mentioned species (e.g., the ציפורת כרמים – vineyard tzippores does not have a bald head, like its counterpart ארבה). This Baraisa holds the פרשה is structured as a כלל ופרט – generalization followed by a specification, so only grasshoppers which have identical features with the פרט (the four mentioned species) are kosher. The second Baraisa, from Rebbe Yishmael’s yeshivah, holds this פרשה is structured as a כלל ופרט וכלל, which allows for including species which are similar to the פרט, even if not identical. Rav Achai eventually explains that the species "סלעם" is superfluous, because it could have been derived from ארבה and חרגול (since it shares their four main characteristics). Therefore, we darshen: אם אינו ענין לגופו – if it has no application for itself, תנהו ענין לראשו ארוך – give it an application for the case of a long-headed grasshopper, teaching that it is also kosher.