Bechoros, Chapter 3, Mishnah 1. We now turn to the practical aspects of the laws of firstborns. The Mishnah seeks to answer a practical question: A Jew buys a cow, goat, or sheep from a non-Jew, and subsequently the animal gives birth to a male offspring - how will he know whether it is the firstborn or not? How will he know if there was a previous birth that opened the womb?
Sometimes we rely on 'mesiach lefi tumo', meaning the casual conversation of a non-Jew, to obtain information. However, this does not help here, since we only rely on the casual conversation of a non-Jew regarding rabbinic matters. Consequently, the buyer faces a question: What should he do with the animal he purchased, after it has given birth to a male offspring, the first one known to him?
The two approaches in the Mishnah:
Let us first present the two approaches, so that they do not get confused with one another later on:
Rabbi Yishmael: If the age of the animal is known, it can be determined at a certain stage that she is too young to have already delivered a previous offspring, and therefore this offspring is necessarily the firstborn.
Rabbi Akiva: This claim is only correct under the assumption that the animal is not exempted from the law of the firstborn except by a previous viable offspring. However, an animal might miscarry, and a few months later give birth to another offspring, and there is no way to know its miscarriage history. Therefore, it must be assumed that everything is in doubt, and the burden of proof is on the one seeking to extract property from his fellow: The owner keeps the offspring, but is concerned that it might be a firstborn, so he lets it graze until it develops a blemish and then he may eat it.
The text of the Mishnah:
"Haloke'ach behemah min hanachri ve'ein yadua im bicherah im lo bicherah" - A Jew who buys a cow, goat, sheep, or donkey from a non-Jew, and the buyer has no knowledge whether the animal previously gave birth or not. Rabbi Yishmael says: We should follow the age, assuming that the true age of the animal can be determined:
"Be'ez bas shenasah" - It is certainly given to the kohen. If the goat gave birth to the offspring in its first year, it is necessarily its first offspring, as a goat cannot give birth to a second offspring within its first year. "Mikan ve'eilach" - From then on, it is a doubt, perhaps it is the first and perhaps it is the second.
"Berachel bas shtayim" - It is certainly given to the kohen, when the offspring is born within the sheep's second year.
From then on, a three-year-old - It is unknown whether it is a first or second offspring.
A few basic facts: The gestation period for goats and sheep is about five months, and for a cow, nine and a half months. The Rishonim already point out that in their time, cows would give birth after two years, and this is certainly the case today: In animal husbandry, it is common for a cow to give birth for the first time within two years. Therefore, despite the text of the Mishnah, it is possible for a cow to have a second healthy and viable offspring before reaching the age of three. Apparently, there has been a change here, perhaps due to selective breeding.
Rabbi Akiva's rejection:
Rabbi Akiva said to him: "Ilu bevalad bilvad habehemah nifteres - kidvarecha" - That is, if it were true that the mother is only exempted from having a firstborn by a preceding viable offspring, your words would indeed be correct. However, there is a possibility of a miscarriage. To this end, Rabbi Akiva brings a source from elsewhere, whose entire purpose is to show that there is a reality of an animal that miscarried, and the miscarriage is considered to have opened the womb, and therefore the first viable offspring, even if it is male, is not a firstborn. And this is what they said regarding the signs of an offspring:
"Siman havalad babehemah dakah - tinuf" - A sign that a small animal, a goat or sheep, has miscarried a miscarriage that exempts it from the firstborn law. 'Tinuf' literally means dirt, and the reference is to a bloody and bubbly mass emerging from the mother. This discharge is not like the animal's normal cycle, and it must be brought to an expert, a veterinarian, or an experienced farmer, who will determine if it is a miscarriage. If so - it is considered to have opened the womb, and if not - it is not.
"Uvegasah - shilya" - In a large animal, a cow or donkey, if the amniotic sac, in which the fetus grows, is seen, it must be assumed that a fetus grew inside it and this is an opening of the womb. Even if the fetus itself is not found, it matters not: We assume it was there and died in the meantime, was absorbed into the body, and disappeared.
"Uve'ishah - shafir veshilya" - In humans, the signs of a miscarriage are the 'shafir', meaning the placenta, which is like a mass of flesh that attaches to the uterus and serves as the blood source for the baby, or the 'shilya', the amniotic sac. The development of a placenta or amniotic sac indicates that a baby grew here, and even if it is not found, it must be assumed that it was there, and was lost and absorbed.
The mention of these signs is incidental. Rabbi Akiva's main point is this: since an animal can miscarry and thereby become exempt from the law of the firstborn, and this can happen while it is still very young, the buyer can never know. Even if he bought a goat in its first year, he does not know if this offspring is its firstborn, or if perhaps it is the second and a miscarriage preceded it. From this, Rabbi Akiva establishes "zeh hakelal" - this is the general rule:
"Kol sheyadua shebicharah, ein kan l'kohen klum" - if it is known with certainty that the animal previously gave birth, the kohen receives nothing, as this is not a firstborn.
"Vechol shelo bicharah, harei zeh l'kohen" - if it is known with certainty that it has never given birth, for example, if it was bought when it was just a few days old, then its first male offspring goes to the kohen as a firstborn.
"Ve'im safek, ye'achel b'mumo labe'alim" - in all other scenarios, when it is unknown whether it is the first or second offspring, the farmer keeps it, and the kohen receives nothing, because the burden of proof rests on the one seeking to extract property from another, and the kohen cannot prove that it is his. However, the owner is not permitted to eat it immediately, as he must be concerned that it might be a firstborn: it is forbidden to work with it or shear it, and he must leave it to graze until it develops a physical blemish, and only then may he eat it.
Rabbi Eliezer ben Yaakov - chararat dam (a lump of blood):
"Behemah gassah sheshaf'ah chararat dam, harei zo tikaver, veniftrah min habechorah" - a cow or a donkey that expelled a hard lump of blood. "Sheshaf'ah" comes from the word for flow or discharge, meaning that it exited the animal. "Chararah" is a borrowed term: a type of cake that would be baked over a fire on the ground, like a piece of hard bread. A "chararat dam" is therefore a hard, red lump of blood, sort of like a brick, that emerges from the animal. Rabbi Eliezer ben Yaakov says: We can assume that this is a firstborn that opened the womb, like a fetus that failed to develop. Therefore, if the animal subsequently gives birth, the new offspring is not a firstborn, since the lump of blood is considered the firstborn that opened the womb.
One might ask: After all, this is nothing but a hard blood clot. Even if we assume that this is indeed the cow's fetus, who says it is a firstborn? First, perhaps it was a female. Second, even if it was a male, not every male is obligated in the laws of the firstborn, such as an offspring that has no resemblance whatsoever to its mother. Why, then, is it treated as a firstborn?
And what is the significance of treating it as a firstborn? A regular firstborn may only be eaten after it has developed a blemish. If it dies before it is eaten, it must be buried, because deriving benefit from it is forbidden and it cannot be fed to dogs. This is the Mishnah's point here: the lump of blood is treated as a firstborn, and it is forbidden to feed it to dogs, but rather it must be buried.
But the question remains, for seemingly this is a double doubt: who says it was a male, and who says that this male is obligated in the laws of the firstborn? The answer is that this law is Rabbinic. Rabbi Eliezer ben Yaakov says that Rabbinically we are required to bury the lump of blood so that the matter will be somewhat publicized. The farmhands will know that something significant occurred to this animal, which holds the status of a firstborn, and when it gives birth to another offspring, they will know it is not a firstborn. If we did not bury it, they would think nothing had happened, and when it later gave birth to a male offspring, they would treat it as a firstborn.
This is not the case with an afterbirth or an amniotic sac: if a watery sac emerged from the cow, there is no need to bury it, and it may even be given to the dogs without any issue. This is because everyone knows that if there was a sac, there was definitely a fetus inside it, and consequently, everyone knows that the next offspring is not considered a firstborn.
In summary: In this Mishnah, we learned about the case of someone who buys an animal from a gentile and it is unknown whether it has already given birth. According to Rabbi Yishmael, we follow the age of the animal: a goat in its first year, a sheep in its second, and a cow or a donkey in their third are definitely given to the kohen, and from then on it is a doubt. Rabbi Akiva rejects this due to the reality of miscarriages, whose signs are a discharge in a small animal, an afterbirth in a large animal, and an amniotic sac and afterbirth in a woman. He establishes: if it is known that it has given birth, the kohen receives nothing; if it is known that it has not given birth, it goes to the kohen; if it is in doubt, it is eaten by the owners when it develops a blemish. Finally, we learned the ruling of Rabbi Eliezer ben Yaakov regarding a lump of blood, which is buried and exempts the animal from the law of the firstborn, and the Rabbinic reason for its burial being to publicize the matter.