We are continuing with the Mishnah in the first chapter of Tractate Bechoros. The next part of the Mishnah brings a novel concept learned from the verse: an offspring that bears no resemblance to its mother is exempt from the law of the firstborn. That is to say, a donkey that gives birth to a strange creature with no resemblance to a donkey - looking like a cow, a dragon, or even a horse, but not a donkey - is exempt from the mitzvah of the firstborn donkey. The same applies to a cow, goat, or sheep that gives birth to a strange male offspring that does not resemble its parents: a cow that gives birth to a creature looking like a donkey - the offspring is exempt from the law of the firstborn on the part of the cow, because it is strange, and it also has no obligation of a firstborn donkey on the part of the donkey, since its mother is not a donkey.
The text of the Mishnah:
"Parah sheyaldah kemin chamor" - a regular cow that gave birth to a strange male offspring, looking exactly like a little donkey.
"O chamor sheyaldah kemin sus" - a donkey that is completely normal in every way, except that it gave birth to a creature looking like a horse and not a donkey. Although horses and donkeys do not differ greatly from one another, this offspring nonetheless looks like a horse.
"Patur min habechorah" - in both cases, there is no mitzvah of the firstborn here. With a cow that gave birth to something like a donkey there is a major novelty, since both cows and donkeys are obligated in the laws of the firstborn, yet nevertheless it is exempt. How much more so with a donkey that gave birth to something like a horse, since the horse itself is not obligated in the laws of the firstborn, and the donkey is also exempt because the offspring does not resemble it.
The Mishnah explicitly notes the source of the law: "Shene'emar: peter chamor, peter chamor, shetei pe'amim" - the phrase "peter chamor" is stated twice in two verses, and from here the Sages derived: "Ad sheyehei hayoled chamor vehanolad chamor" - the obligation does not take effect unless both the mother is a donkey and the emerging offspring looks like a donkey.
"Umah hem ba'achilah?":
The Mishnah continues and asks what their status is concerning consumption. Seemingly, with a donkey that gave birth to a creature looking like a horse there is no question: the offspring is certainly not kosher, since it looks like a horse and its mother is a donkey. For this reason, the Bartenura's textual variant is not "umah hem ba'achilah" but rather "umah hu ba'achilah" - in the singular form, meaning the question is directed at the second case: a cow that gave birth to a strange offspring. Put simply: a cow that gave birth to a calf that does not have split hooves but rather hooves like a horse, or has no legs at all - it is missing the basic sign of kashrus. What is its law?
"Behemah tehorah sheyaldah kemin behemah temeiah - mutar ba'achilah" - a kosher animal that gave birth to an offspring lacking the signs of a kosher animal, such as not having split hooves, is permitted for consumption.
"Utemeiah sheyaldah kemin behemah tehorah - asur ba'achilah" - a non-kosher animal, such as a donkey, that miraculously gave birth to a strange offspring that possesses split hooves, is forbidden for consumption.
The rule: "Hayozei min hatamei tamei vehayozei min hatahor tahor":
The reason for this is a fundamental rule in the laws of kashrus: the product of a kosher animal is kosher, and the product of a non-kosher animal is not kosher. Therefore, a cow that gave birth to a calf lacking legs or lacking hooves - the offspring is kosher, and vice versa. This rule applies across the board: for this reason, an ostrich egg is not kosher, since the ostrich is not kosher, and camel milk is not kosher because the camel is not kosher.
Only two matters might appear to be exceptions to the rule, yet in truth they are not exceptions at all:
Bee honey: Insects are not kosher, with the exception of four species of locusts, and the bee is certainly not counted among them - yet despite this, honey is kosher. The Gemara brings two reasons: one, a scriptural decree; and the second, that the bee does not actually produce the honey at all. The bee collects the pollen into a sort of sac in its body, where enzymes act upon it, and afterward it regurgitates it. This is not a product of the bee, but rather fermented nectar, and therefore it is considered a plant product and retains its kosher status. It is amazing how close the words of the Sages are to biological reality, and how they knew what takes place inside the bee's body during the production of honey. In contrast, other bee products, such as propolis, are not kosher, since they are a product of the bee itself - similar to camel milk.
Mother's milk: Babies nurse mother's milk, and it is kosher. While there is a Rabbinic prohibition for anyone who is not a baby to nurse from a woman, due to it being repulsive - like nursing from a creeping creature (sheretz) - from the strict letter of the law there is no kashrus prohibition here at all. The reason for this is that human beings are not animals, and the laws of kashrus do not apply to them.
A non-kosher fish that swallowed a kosher fish:
The final case in the Mishnah addresses an obvious, yet excellent, "what if" question: What is the status of a kosher animal that swallowed a non-kosher animal? For instance, a salmon that is found to contain a frog, a small shark, or a snail. It is obvious that these are not products of the salmon but are merely located inside it, and therefore they are not kosher. The same applies in reverse: A shark that swallowed a salmon, and upon opening it the salmon is found inside - the shark is not kosher, but the salmon inside it is kosher, since it did not grow from the shark.
"Dag tamei shebala dag tahor - mutar ba'achilah" - this refers to the kosher fish inside, which is permitted to be eaten. This law applies no matter where the fish is found in the digestive tract, and there is no need to actually witness the swallowing or to find it specifically in its mouth. Wherever it is found, as long as it is not digested and still looks like a salmon - it remains as kosher as a salmon.
"Vetahor shebala dag tamei - asur ba'achilah, lefi she'eino gidulav" - the non-kosher oyster or small shark did not grow from the kosher salmon, but merely entered its mouth. Therefore, they retain their prohibited status and may not be eaten.
In summary: In this section, we learned that a strange offspring bearing no resemblance to its mother is exempt from the laws of the firstborn, as derived from the repetition of "peter chamor" - requiring that both the mother and the offspring be donkeys. Regarding consumption, we discussed the rule that "what emerges from the impure is impure, and what emerges from the pure is pure," as well as the two apparent exceptions to this rule - bee honey and human breast milk. Finally, we learned that a fish that swallowed another fish does not change the kosher status of the swallowed fish, since it did not grow from it.