Halakhah su Levitico 11:42

In comments published in Hiddushei ha-Graḥ al ha-Shas, ed. Y. Cohen (Jerusalem, 5729), Hullin 67a, the Brisker Rav, R. Yitzchak Ze'ev Soloveitchik, is quoted as espousing the position that, although identity as a member of a forbidden animal species is established by progenital relationship without regard to the presence or absence in the progeny of the anatomical criteria enumerated by Scripture, that is not the case with regard to sherazim or "swarming things." The Brisker Rav observes that Scripture neither names species forbidden as "creeping things" nor does it spell out identifying criteria. The prohibition is couched simply in the phrase "all swarming things that swarm upon the earth you shall not eat" (Leviticus 11:42). Accordingly, he argues, the fact that the organism "swarms" is the determining factor in establishing the prohibited nature of such a creature.⁸¹For further discussion of the Brisker Rav’s view see chapter seven of this volume, p. 221, note 34.

The species which originate in dust heaps and carcasses, such as maggots, worms and their like and which are born, not through intercourse between male and female, but out of putrefaction of dung and the like are called "creeping things that move upon the earth" (Leviticus 11:44). … On the other hand, "all creeping things that creep upon the earth" (Leviticus 11:42) refers to such that procreate by intercourse between male and female.

But the Sages forbade the blood of people because of appearances. And therefore they said (Keritot 22a), "Blood that is between the teeth, he should suck and swallow; and that is on the bread, he should scrape it off of it and eat the bread." And so [too] is the blood of eggs permitted - as I do not call it the blood of the fowl, and it is not from the meat, even if it has started to form. And such is the opinion of our teachers, the Masters of the Tosafot on Chullin 64b, s.v. vehu, and as is implied from the simple meaning of the bereita in Keritot 21a. This is the law of the Torah. But the Sages forbade an egg that has [been] formed, and supported the thing with the verse of "the swarming creature that swarms" (Leviticus 11:42). And hence they forbade the blood of eggs on account of the doubt - that [perhaps] it formed. But anything that does not have a doubt of formation, they only forbade on account of appearances. And so, [regarding] blood of eggs found in the white, one should throw out the blood and eat the rest. But there are those that are stringent when it is found on the union and outside of the union [of the egg], to forbid the whole egg.