Talking Talmud

Rav Huna says not to pour beer in the night with a filter, lest a creepy crawlie comes outside of the filter and into the beer, which would be a problem to drink. How does one distinguish between that which is just the normal manner of growth, which would be acceptable, and when there's a problem of unusual bug activity. Also, an investigation into the question of worms - in that they come from outside of the animal, as compared to internal "spontaneous generation." What about larvae? And what about fish larvae? Also, again, "according to its kind" - for a worm and a scorpion and a beetle and a centipede. That is, those creepy crawlies that are not considered kosher. Plus, the Leviathan, which doesn't reproduce, is a kosher fish -- and it will be the feast for the righteous in the future.

Fish that have scales for part of their lives -- are likely to be kosher. But fish that have fins and no scales are not kosher. But if scales are all that matters, why doesn't the Torah just say scales? Why mention fins at all? The Gemara gives several answers. Also, the Gemara focuses on the language of the permitted and prohibited -- both of which forms are stated. Plus, eating that which grow in water is permitted, say, pits and ditches, but what about vessels? How did these creatures emerge from the water?!

Birds that claw their prey are not kosher, though there are other signs too, of course. Plus, how the bird sits on a line with its "toes" divided across the line is an indication of a possibly kosher bird. A bird that catches another bird in the air - not kosher. Also, which birds does the bird under question dwell among? Plus - grasshoppers! To be kosher, the legs, the hopping, and the name of the creature need to be in line with the kosher requirements. Each type of kosher grasshopper is described as "according to its kind," in the Torah's presentation of them. Plus, the organization of the generalizations and specifications in the Torah makes a difference as well -- regarding the traits that are required for a grasshopper to be kosher. The common traits matter - even in comparison to the specifics that might apply to a given species.

Eggs! They can bought from anyone, including idolators, without concern that they came via a nevilah or treyfa. The eggs themselves are identifiable as coming from a kosher species (or not) -- in terms of the shape of the egg itself, and more other ways of distinguishing one from another. But not if the egg itself is mixed. Also, if eggs are cooked together -- kosher and non-kosher -- the kosher eggs are still allowed. Unfertilized eggs are also acceptable, even if the hen sat on the egg for a long time. A droplet of blood on the egg won't invalidate it either - as long as you discard that droplet of blood. But if the blood was in the yolk area of the egg, then the entirety needs to be discarded.

There are 24 non-kosher birds, and there's a long chain of transmission to that effect, but if you count the birds in the Torah, the list in Leviticus has 20 birds and the comparable list in Deuteronomy has 21 birds. So where is the count of 24 to be found? The Gemara explains. By including those birds that come along with the other ones (a few times), the count works. Also, a hundred varieties of one particular kind of bird -- from within the 24. Plus, in the lists of kosher animals vs. non-kosher animals, the Torah includes the shorter one, whether kosher or non-kosher. Also, the Gemara acknowledges that one can have halakhic expertise or animal expertise or both, but they are not the same bodies of knowledge, and the one studying Jewish law must draw on other arenas of knowledge.