Rambam - 3 Chapters a Day

In contrast to temporary blemishes which do not disqualify a firstborn animal from being sacrificed forever. (As long as the temporary blemish remains, however, the animal cannot be sacrificed.)

As stated in Hilchot Issurei Mizbeiach 1:10, it is a mitzvah to redeem consecrated animals that became blemished.

I.e., whether in Eretz Yisrael or in the Diaspora.

Chapter 2.

For the firstborn offering applies only to male animals, a stated in Chapter 1, Halachah 1.

Hilchot Issurei Mizbeiach 2:6 states that there are 73 blemishes that disqualify an animal. However, six of them are not applicable to male animals.

Ibid.:8; these represent ailments that detract from the animal’s appearance, but not substantially enough to disqualify it.

Only then is it permitted to slaughter it.

lbid.:6-7.

I.e., a man or a woman performed a sexual act with it.

Were two witnesses to observe a human performing a sexual act with an animal or it killing a person, it should be executed. (Hilchot Issurei Mizbeiach 1:17; Hilchot Nizkei Mammon 10:1). In this instance, the testimony is not sufficient for that punishment.

Even though it was not actually worshiped.

It is considered unfit to be offered as a sacrifice.

Hilchot Issurei Mizbeiach 2:9.

Since it did not emerge through the womb, it is not given the status of a firstborn. Parallels to these rulings exist with regard to humans; see Hilchot Bikkurim UMatanot Kehunah 11:16.

Thus it cannot be considered as the firstborn.

I.e., it has both male and female genital organs.

I.e., it is not considered as a blemished firstborn, nor is there a doubt about its status. The rationale is that in this context, it is considered as an independent type of being (Bechorot 41a).

Activities forbidden for a firstborn (Hilchot Me’ilah 1:9).

I.e., a mound of flesh covers its genitals and its gender cannot be determined.

I.e., because of the possibility that it is a firstborn, work may not be performed with it and it must be left to pasture until it contracts a blemish that disqualifies it. Nevertheless, once it contracts such a blemish, there is no obligation to give it to a priest, for perhaps it is not a firstborn. On the contrary, we follow the principle that if someone (in this instance, a priest) desires to expropriate property (the firstborn) from another person (the owner), the burden of proof is on the former. Since he cannot prove that it is a firstborn, the owner is allowed to retain possession. See Chapter 5, Halachah 3.

The phrase could also be read as “the firstborn ox,” thus allowing for the interpretation cited by the Rambam. The verse continues to speak of “the firstborn of a sheep” and “the firstborn of a goat,” indicating that the same rule applies to these animals.

An offspring of a sheep that resembles a goat, or the offspring of a goat that resembles a sheep.

And must be given to a priest.

Hilchot Issurei Mizbeiach 3:5.

There is no obligation to redeem it as a donkey must be redeemed (Hilchot Bikkurim UMatanot Kehunah 12:18). The Lechem Mishneh notes that the Talmud derives both these concepts from the same verse and questions how the Rambam can accept both interpretations.

With regard to the permission to partake of such an animal, see Hilchot Ma’achalot Assurot 1:4.

For a firstborn donkey must be redeemed by exchanging it for a lamb, as Exodus 13:13 states: “The first issue of a donkey you shall redeem with a lamb. See Hilchot Bikkurim UMatanot Kehunah, ch. 12.

The rationale is that the same principle cited in note 21 in support of the owner can now be cited in support of the priest. Since there is a question regarding the animal’s status and it is not certain that it is a firstborn, a priest may not take it. On the other hand, once the priest took it, that argument can be reversed: It is not certain that it is not a firstborn and it is now in the possession of the priest. Therefore if someone (in this instance, the owner) desires to expropriate property (the firstborn) from another person (the priest), the burden of proof is on the former. Since he cannot prove that it is not a firstborn, the priest is allowed to retain possession.
Many have questioned the Rambam’s decision. Indeed, volumes have been written about this issue. With regard to practice, there is a difference of opinion regarding the matter between Sephardic and Ashkenazic authorities. The Sephardic authorities (see Shulchan Aruch, Yoreh De’ah 315:1) follow the Rambam’s view and allow the priest to maintain possession. The Ashkenazic authorities (Tur, Rama, loc. cit.) follow the opinion of Rabbenu Asher who states that since the priest had no right to take the animal, it is expropriated from his possession.

Rashi (Bechorot 34a) interprets this as referring to a priest to whom the firstborn animal was given. It could, however, be understood as applying to an Israelite as well. He would prefer that the animal be blemished, so that he could give it to the priest and cease caring for it.

As stated in Sefer HaMitzvot (negative commandment 97) and Sefer HaChinuch (mitzvah 287) (see Hilchot Issurei Mizbeiach 1:7), one of the Torah’s 365 prohibitions is causing a sacrificial animal to incur a blemish.

And not given the opportunity of benefiting from his transgression.

Compare to Hilchot Pesulei HaMukdashim 18:5.

Compare to Hilchot Sh’vitat Yom Tov 7:4; Hilchot Shemitah 1:13; Hilchot Choveil 7:3.

See Halachah 12.

He did not give the gentile instructions, nor did he know what the gentile would do.

This is a decree, enacted as a safeguard so that a person will not perform an act that directly causes a firstborn to be blemished.

Indeed, the example given by the Rambam reflects a story that transpired concerning a firstborn owned by Rabbi Tzadok, one of the foremost Sages of the time. He protested that as a Sage, leniency should be granted him for he would never blemish a firstborn by hand. The Sages, however, did not accept his argument and prohibited him from slaughtering the animal.

And not at this immediate time.

Even though he intentionally kicked the animal, his intent was not to cause a blemish, but to prevent it from pursuing him.

Bechorot 5:3 relates that children were playing with animals and tied their tails together. The animals ran in opposite directions pulling the tail off an animal that happened to be a firstborn. The court ruled that the firstborn could be slaughtered. When the children heard the ruling and saw the owner was happy, they did the same to other firstborn animals. Since they purposefully acted to blemish the firstborn, those animals were not permitted to be slaughtered.

That same source relates that a gentile saw a firstborn animal that was not cared for and asked its owner why it was left in that condition. The owner explained that he was waiting for it to become blemished. The gentile then hacked its ear. The Sages ruled that it was permitted to slaughter it. When the gentile heard their decision and saw that the owner was happy, he blemished other firstborn animals. The Sages ruled that it was forbidden to slaughter them, because the gentile acted for the benefit of the Jews.

We have freely translated an idiom used by Bechorot 5:3, et al. It refers to a condition where the animal turns dark red and its temperature rises. If it is not treated quickly, it could die.

Even though the person intentionally let the animal’s blood, since he did not intentionally plan to blemish the animal, the Sages did not forbid making use of the animal.

I.e., while it is in its mother’s womb, one of its limbs may be maimed so that it will emerge blemished. Until the animal emerges from the womb, the sanctity of a firstborn animal is not conveyed upon it. Hence causing it to become blemished does not violate a Scriptural prohibition.

And in this way, the animal will be prevented from being offered as a sacrifice.

Although generally, second hand testimony is not accepted, leniency is granted in this instance, because all that is involved is a Rabbinic safeguard.

Whose testimony is not accepted according to Scriptural Law and even with regard to almost all questions of Rabbinic Law.

This is also somewhat of a leniency, because besides the fact that only one person is involved, a shepherd is often not acceptable as a witness.

We do not suspect that the shepherd will perform the transgression of blemishing an animal so that it will be ordinary property in the priest’s possession and perhaps, the priest will give him a portion (Rav Yosef Corcus).

I.e., during the time the firstborn is kept in its owner’s possession, before it is given to the priest. See Chapter I, Halachah 14.

The Rambam’s decision is quoted by the Shulchan Aruch, Yoreh De’ah 314:2. The Ashkenazic authorities (Tur, Rama, Zoe. cit.) follow the opinion of Rabbenu Asher who maintains that the word of a shepherd who is a priest can also be accepted. Since we see that the word of a priest’s own family is accepted with regard to such matters (see the following halachah), certainly, the priest’s word should be accepted in this instance. The Kessef Mishneh and Rav Yosef Corcus explain the Rambam’s interpretation of Bechorot 35a and in that manner, substantiate his ruling.

I.e., that one will testify on behalf of the other at a later date. This reflects a general principle applicable in other contexts; see Hilchot Ma’achalot Assurot 18:17, 20:11; Hilchot Ma’aser 12:7.

The Kessef Mishneh suggests that the word “all” is included to refer even to priests who are Torah scholars and observant with regard to other matters.

Even though this involves the violation of a transgression.

From the Rambam’s words, it appears that this suspicion applied even in the era of the Temple. Although the firstborn would be given to the priests in all instances, it was suspected that the priests would rather partake of it as ordinary meat, than take the trouble to bring to -Jerusalem and offer it as a sacrifice.

This also is a general principle applicable in other contexts; see Hilchot Ma’aser 12:17.

See Hilchot Edut 13:6.

His word is accepted as stated in Halachah 15.

And was not brought about with the knowledge of the priest.

An expert who is knowledgeable whether a blemish is permanent or not, as explained in the following chapter. Rav Yosef Corcus states that it is not necessary for the priest to name the expert who rendered the lenient ruling. Mentioning the identity of the expert would be sufficient to permit the slaughter of the animal in its own right. Nevertheless, since the priest is not suspect to violate the severe transgression of slaughtering consecrated animals outside the Temple Courtyard, there is no need for the expert’s name to be mentioned.
This perspective is not accepted by all authorities. Rabbenu Asher differs and requires that the name of the expert be stated. The Shulchan Aruch (Yoreh De ‘ah 314:7) follows the Rambam’s perspective and does not make such a stipulation, Although the Tur (op. cit.) follows the ruling of Rabbenu Asher, the Rama does not mention that view.

See Hilchot Ma’aseh HaKorbanot 18:2-4; see also Hilchot Shegagot 1:2-4. Although Halachah 17 states 11 priest is suspect of causing a firstborn to become blemished, that transgression is not punishable by karet. Hence that ruling is more stringent.

Rav Yosef Corcus states that it would appear that it _is necessary for the priest to mention the name of the Israelite who gave him the firstborn animal. Otherwise, it is not that likely that the matter would be revealed. He states, however, that there is no indication in the Rambam’s words that this is in fact necessary. He explains that perhaps no such requirement was made, because people will have known who was the owner of the firstborn, because it was in his possession for several weeks.
In his Kessef Mishneh, Rav Yosef Caro notes this issue and states that Rabbenu Asher differs and requires that the Israelite be named. In his Shulchan Aruch (Yoreh De’ah 314:8), he quotes the Rambam’s ruling. In this instance, as well, although the Tur (op. cit.) follows the ruling of Rabbenu Asher, the Rama does not mention that view.

See Hilchot Kiddush HaChodesh 3:14; Hilchot Gerushin 12:15; Hilchot Yibbum VeChalitzah 3:5, where this rationale is also stated.

These laws did not only apply with regard to firstborn animals in the era of the Temple, but in subsequent periods of time, as indicated by the fact that Sanhedrin Sa speaks of Rabbah bar Chanah receiving such license from Rav Yehudah HaNasi more than 100 years after the destruction of the Temple.

The head of the Sanhedrin of 71 judges. Even if the expert was a distinguished sage, unless he was granted permission by the nasi, he should not issue such rulings (Yoma 78a).

If there is an expert in the area, a person may not even slaughter an animal with the types of blemishes mentioned in the following halachah without the expert granting permission.

We do not fear that he will intentionally permit the slaughter of an animal that is unblemished. Rather, the fear is that his desire to be free of the obligation to care for the firstborn animal will cause him to make an improper judgment and permit its slaughter when that was uncalled for.

The Shulchan Aruch (Yoreh De’ah 309:2) define this as referring to “men of some wisdom, but not experts.”

Needless to say, this applies to an animal born in the Diaspora (Kessef Mishneh).

If, however, it is not obvious that an animal is blemished, no one other than an expert may grant license for its slaughter.

I.e., an unblemished firstborn.

I.e., after it is established that the animal is blemished, it no longer possesses any sacred status. It must, however, be given to the priests. Nevertheless, this is a far less severe transgression and we fear that some of the common people may violate it.

And thus it definitely no longer possesses a sacred quality and can be eaten by an ordinary person.

For if he intended to take the animal for himself, he could have done so without bringing it to the expert.

Bechorot 28a states that this is a decree, initiated as a safeguard. There are some blemishes in the eye which will change color after the slaughter of an animal and it is possible that a condition that is not truly a blemish will be permitted. Hence to ensure that inappropriate leniency was not granted in that instance, our Sages forbade inspecting all blemishes after the animal was slaughtered.

See Hilchot Pesulei HaMukdashim 19:11.

Which is one of the disqualifying blemishes, as stated in Hilchot Bi’at HaMikdash 7:8.

Kneading the animal’s genital area will force the second testicle into its sac.

Even though the animal did possess a second testicle, since it did not come out despite the kneading process, it is considered as a disqualifying blemish (Rav Yosef Corcus, based on Bechorot 40a).

For perhaps, had the animal’s genital area been kneaded, the testicle would have emerged. If, however, a second testicle is not found, the animal is permitted.

This applies even when in truth the animal was blemished. Since it is forbidden to benefit from it, as stated in Halachah 4, the person who caused it to be slaughtered is considered as one who damaged his colleague’s property and he is responsible for reparations.

A goat or a sheep.

A calf.

For this reason, the person is not required to pay half the animal’s worth.

See Hilchot Nizkei Mammon 5:1-2 which explains that since small animals frequently graze in other people's fields and damage the crops, our Sages forbade raising small animals in Eretz Yisrael. For that reason, the owner is further penalized and the person who permitted the slaughter of the animal is released from responsibility for an additional fourth of the animal's worth.
In the Diaspora, this rationale is not relevant and this further penalty is not exacted and the person who permitted the slaughter of the animal is required to pay half its worth. The Shulchan Aruch, Yoreh De'ah 310:3, states that, in that era, most of the fields in Eretz Yisrael were not owned by Jews. Hence, the laws that apply in the Diaspora apply there. Today in Eretz Yisrael, there is reason to say that the rulings followed in the era of the Talmud should be reinstated.
The Ra’avad offers a different interpretation of the reasons why the owner receives only these amounts. Providing food for large animal costs the owner substantially. Since he will be saving that money, the amount he receives is less. Similarly, the cost of hiring a shepherd for a small animal is great, for it cannot be raised in the settled areas of Eretz Yisrael and must be taken to the distant forests. Hence, the damages required for its loss are less.

For a person should render Torah rulings without charge, emulating the example of Moses our teacher. Thus on Deuteronomy 4:5: “Behold I taught you,” Bechorot 29a comments: “Just as I [Moses] taught you free of charge, you should teach free of charge.” With regard to the entire concept of receiving wages for teaching the Torah, see Hilchot Talmud Torah, ch. 3, where the subject is discussed in detail.

Bechorot 28a states that if a person receives a fee for inspecting a firstborn, an animal should not be slaughtered on the basis of his ruling unless he is “like Ila in Yavneh.” In his gloss to that passage, the Ramban states that Ila was a great authority on blemishes. Everyone would bring their firstborn animals to him and thus he would not have time to perform his work. Hence the Sages granted him license to receive a fee for his services.

In this way, he will have no desire to classify it as blemished, because he will be paid regardless (Bechorot 28b).

In this way, he will have no desire to classify it as unblemished, because he will not receive any extra payment for this ruling (ibid.). Tosafot ask: If so, one might think that he would classify it as blemished so that he would not be forced to inspect it again. They reply: We do not suspect that a sage would permit a transgression to be performed (slaughtering an unblemished firstborn which is a sacred animal outside the Temple Courtyard).

The entire body of the firstborn animal is consecrated and it is forbidden to make personal use of anything from that animal. Because this person is suspect of selling firstborn animals as ordinary property, we take precautions regarding all products that could come from such an animal: its meat, its hide, and its wool.

Even though the concept of the holiness of a firstborn animal does not apply with regard to wild animals, this safeguard is employed, because of the reason stated by the Rambam.

Which could never be endowed with the holiness of a firstborn.

Whitening wool does not involve much time or activity. Hence it is possible that the wool came from a firstborn animal.

I.e., that it appears that it has been taken directly from an animal. Thus there is a likelihood that the wool came from a firstborn.

These three activities all take time and hence, the product is permitted for the reason the Rambam proceeds to state.

For this is a matter that could be known by his neighbors, workers, and the like and could easily become the topic of conversation in a rural environment.

See Hilchot Mechirah 16:12. Even though the person benefited from the forbidden substance, after he realizes that it is forbidden, his regret is so great that the benefit is not considered significant.

And thus slaughtered as a sacrificial animal.

If it was discovered to be treifah before it was skinned, the hide must be buried together with the meat (Kessef Mishneh).

Hilchot Pesulei HaMukdashim 19:9.

As is the law concerning a firstborn animal that died. Since it was treifah, its slaughter is not significant and there is no difference between it and an animal that died naturally.
One might ask: In Chapter I, Halachah 3, it was stated that a blemished firstborn animal is a priest's private property and he may do with it as he sees fit, even feed it to a gentile. Why then can the animal here not be given to a gentile? In resolution, it can be explained that once the firstborn is given to a priest. and he may partake of it, he may do with it as he sees fit. In this instance, however, the priest never had the license to partake of the firstborn. Hence, he cannot use it for other purposes.

Rabbenu Asher differs and maintains that it is forbidden to benefit from the hide and it must be buried, even in such a situation. His opinion is cited by the Tur and the Shulchan Aruch, Yoreh De’ah 307:2.

I.e., when an unblemished animal was offered as a sacrifice or when a blemished animal was slaughtered according to the ruling of an expert.

As explained in Hilchot Me’ilah 1:7-9, there is a Scriptural prohibition against shearing a firstborn animal. This prohibition continues to apply even if the animal was blemished. Wool which is shed by an animal is not, however, forbidden by Scriptural Law. Nevertheless, Halachah 10 of that source states that wool shed or removed from a firstborn animal is forbidden for the reason stated by the Rambam.

Once a blemished animal is permitted and slaughtered, its wool may be used.

In contrast, we assume that a person will offer a sacrifice that comes to secure atonement as soon as possible, for he sincerely desires the atonement.

Chapter 1, Halachah 8.

I.e., the wool was already severed from the animal’s hide, but remained entangled with its other wool.

Since wool that was shed during an animal’s lifetime is forbidden only by Rabbinic decree and, in this instance, it is not apparent that the wool was shed during the animal’s lifetime, our Sages ruled leniently.

Generally, when a forbidden substance that is dry becomes intermingled with a larger amount of a permitted substance that is dry, since the majority of the mixture is permitted, the forbidden substance is considered insignificant. Therefore the mixture may be used. This, however, does not apply if the forbidden substance is an entity of significant importance. Since it is important, it is never considered to be an insignificant element of the mixture. Therefore is never permitted regardless of the amount of the permitted substance. See Hilchot Ma’achalot Assurot 16:9.

In his Commentary to the Mishnah (Orlah 3:2), the Rambam translates the term sit into Arabic. Most commentaries interpret his statements as meaning “the distance between the top of the thumb and the next finger [when the fingers are spread out]. This is one-sixth of the distance between the thumb and the middle finger [when the fingers are not spread out].” Rav Kappach notes that in fact such a calculation will not be accurate. He interprets the Rambam’s words as defining a sit as half the distanoe between the index finger and the middle finger when spread out. This he maintains is two thumbbreadths.
In his Commentary to the Mishnah (Shabbat 13:4), the Rambam differentiates between “the width of a sit” and “the full length of a sit.” As indicated by Hilchot Shabbat 9:20, “the full length of a sit” is two thumbbreadths. In contrast, as stated (ibid.:7), “the width of a sit” is two thirds of a zeret, i.e., three thumbbreadths.

This ruling is based on the same principle as the first clause. Since the full length of a sit of wool is a significant entity and it is not distinct and thus cannot easily be removed, the entire garment is forbidden.

A consecrated entity must be redeemed before it can be used for ordinary purposes. Since the wool from the consecrated animal could be redeemed and then it would be permitted to use the entity, it is never considered to be insignificant. The rationale is that there is no reason to permit the entity because it is insignificant when there is a way to cause it to be permitted in a manner that resolves all difficulties (Kessef Mishneh in explanation of the Ra’avad; see Hilchot Ma’achalot Assurot 15:10).

Using the singular form of the words.

The Kessef Mishneh states that a partner has a share in the entire animal. Hence, even if the gentile’s partnership is minimal, it cannot be said that this animal belongs to a Jew entirely. This approach, however, does not seem to be accepted by all authorities. The Siftei Cohen, Yoreh De’ah 320:4, explains that the rationale for the halachah is that it is possible that the gentile’s share encompasses an organ that is of vital importance like the heart or the brain.

The mother or the fetus.

Since the gentile does not own or have a share in the animal as a whole different laws apply.

There is a difference of opinion concerning the matter in Bechorot 3a. There are Rabbis who follow the more stringent view that maintains that this leniency applies only when gentile’s share encompasses an organ whose absence would render the animal treifah. The Shulchan Aruch, Yoreh De’ah 320:4 quotes the Rambam’s ruling, but the Siftei Cohen advises following the stringency required by the other opinions as an initial preference.

The Kessef Mishneh asks: “What limb could be cut off without causing the animal to be considered unblemished?” and explains that it refers to an extra toe on the animal’s hooves.

Which would be a firstborn.

He buys - or in the following instance - he sells the fetus, but not the cow.

It is forbidden to sell a large animal to a gentile, as stated in Hilchot Shabbat 20:3.

For, as indicated by the following halachah, both the mother and the offspring must be owned by a Jew.

As stated in Hilchot Shabbat, loc. cit., a person who sells a large animal to a gentile is penalized and required to buy it back, even at a loss. This penalty is not exacted for selling a fetus. Tosafot, Bechorot 13a, places the emphasis on the fact that the person prevented the mitzvah of the firstborn from being carried out. Even though one might think a person should be penalized for such a deed, leniency is granted.

This was one of the common arrangements made for caring for sheep and cattle in the Talmudic era. Instead of paying the cowherd or shepherd in cash, he would be paid by receiving a share of the animal’s offspring.

Because of the gentile’s ownership.

The mother and the offspring.

This also was an arrangement to enable a shepherd to earn a livelihood without the owner of the sheep paying his wages in cash. This arrangement is called tzon barzel and is described by the Rambam in Hilchot Malveh ViLoveh 8:12: [A person] owned 100 sheep. [A shepherd] accepted the responsibility of caring for them on the condition that the shearing, offspring, and milk would be split between them... [Included in the agreement is the condition that] if the sheep die, the shepherd must make restitution for them.

I.e., since the gentile has a claim on the offspring, there is no obligation to separate the firstborn from the third generation.

I.e., the fourth generation.

When quoting this law, the Shulchan Aruch, Yoreh De’ah 320:6, adds that if the Jew extends the gentile’s lien to the later generations, their offspring are also free from the requirements of firstborn animals.

As the Rambam explains in Hilchot Mechirah, ch. 3, according to Scriptural Law, a transaction (kinyan) is completed through the exchange of money. Nevertheless, our Sages ordained that transactions between Jews should be completed through meshichah, i.e., drawing it after one for a short distance.
This institution, however, was not necessarily accepted by the secular laws by which most gentiles abide. Hence if a gentile desired and a Jew agreed that the transaction between them be completed through the payment of money, that agreement is binding (see Hilchot Zechiyah UMatanah 1:14).

I.e., if the animal gives birth to its firstborn after the payment of the money, the laws of the firstborn apply even though the Jew had not taken possession of it through meshichah.

The laws stated in the following halachah apply to it.

The owner is required to set the animal aside as a firstborn, because of the doubt. Nevertheless, he may not have it offered in the Temple as a sacrifice, for perhaps it is an ordinary animal and one would transgress by slaughtering an ordinary animal in the Temple Courtyard. Hence it is allowed to pasture until it contracts a blemish. Once it is blemished, it need not be given to the priest for the reason the Rambam proceeds to explain. It may be eaten by its owners, because there is no sacred quality connected with it. See Chapter 5, Halachah 3.

In this instance, the priest.

The firstborn.

The owner.

Since the priest cannot prove that the animal is a firstborn, the owner is allowed to retain possession. This is a general principle applicable in many contexts of Jewish Law; see Hilchot Terumot 10:14, Hilchot Mechirah 20:5, et al.
When quoting this law, the Shulchan Aruch, Yoreh De’ah 316:1, states that both the stringencies and leniencies stated above apply whether the animal is within its first year of life (and thus is less likely to have given birth previously), as stated in Halachah 10, or after its first year of life (when it is more likely to have given birth). Similarly, they apply even if the gentile mentions in the course of conversation that the animal has already given birth previously.

Bechorot 24a explains that this ruling is based on the assumption that an animal will not have mercy on a young animal unless it gave birth previously.

See Hilchot Ma’achalot Assurot 1:4 which states that, because of the doubt, it is forbidden to partake of such an animal. Thus it is clear that we are not certain that it is the offspring of the mother. Nevertheless, the probability is significant enough to free the offspring from the requirements of a firstborn animal.

The Shulchan Aruch, loc. cit.:3, quotes the Rambam’s ruling. The Tur and the Rama differ and maintain that we do not rely on the assumption mentioned by the Rambam. They do, however, mention that if, in the course of conversation, the gentile states that the animal has given birth, his word may be accepted if it is providing milk. This, however, applies only when speaking of a cow for which the above assumption is more applicable. Goats, by contrast, often provide milk before giving birth.

The Rambam’s ruling is quoted by the Shulchan Aruch, loc. eit.:6. The Tur and the Rama differ and maintain that the animal should be considered as a firstborn of doubtful status and the laws mentioned in Halachah 7 apply.

I.e., people at large will not be able to discern the nature of the discharge, but an experienced shepherd could.

For we accept their word and consider it as if the animal has given birth already.

In which instance, it is likely that the animal did not give birth previously.

And thus is governed by the laws mentioned in Halachah 7.

This principle is also applied in Hilchot Issurei Bi’ah 10:14 and Hilchot Temurah 4:10.

Chapter 2, Halachah 6.

Because of the combination of these factors, the likelihood is that the offspring carried in the placenta was not a male obligated in the requirements of the firstborn. Hence, the placenta is not considered as consecrated.

As a portion of a consecrated animal.

For even if we assume that a fetus was also discharged, as mentioned in the previous halachah, the majority of firstborn fetuses are not bound by the requirements of a firstborn animal.

Hilchot Issurei Bi’ah 10:1-2.

Thus the laws of impurity associated with childbirth do not apply to her and, if this was her first pregnancy, a male born afterwards is considered as the firstborn.

See Halachah 10 for the definition of this term.

The commentaries have questioned - without resolving - the apparent redundancy in the Rambam’s words. Rashi (Bechorot 22a) interprets the source for the Rambam’s statements differently.

According to Rav Yosef Corcus, the Rambam is saying that it is possible to classify an animal as a firstborn in the following situation. Its mother had not given birth previously. The mother discharged a tinuf, afterwards engaged in relations with a male, and then was kept alone. If it gave birth within six months of the discharge of the tinuf, we assume that the discharge was not a miscarriage and was merely blood and not a fetus.

I.e., it went out to the field in the morning looking pregnant and returned in the evening looking like an ordinary animal.

See Halachah 7.
Bechorot 29a states that, generally, an animal which miscarries discharges an entity that causes her offspring to be exempted from the requirements of the firstborn. However, in such an instance, it discharges a tinuf first and this animal did not discharge a tinuf Rav Yosef Corcus questions whether that is the Rambam’s intent as well. When quoting this law, the Shulchan Aruch, Yoreh De’ah 315:4, quotes the wording used by the Rambam without emendation.

And thus does not exempt an offspring born afterwards from the requirements of the firstborn.

i.e., a weaving needle. The needle used for the woof is, however, larger than that used for the warp (Bechorot 22a).

Compare to the final clause of the halachah. Since the limbs are being cut up within the animal, extracted individually, and fed to the dogs immediately, it never existed as a complete entity outside its mother’s womb. Consequently, such a fetus is not considered to have been “born,” nor to have “opened its mother’s womb.” Its meat is not considered consecrated and hence may be fed to the dogs.

The Rambam’s ruling is quoted by the Shulchan Aruch, Yoreh De’ah 319:1. The Tur and the Rama, by contrast, follow the opinion of Rabbenu Asher who maintains that the second animal should not be considered a firstborn.
Rav Yosef Corcus asks: Why is such a situation considered more lenient than that of a tinuf or a flow of blood mentioned above? He answers that in those situations, we assume that the fetus emerged whole, while here, we know that it did not.

It is considered to have been “born.” Hence it is consecrated and must be buried; see Chapter 3, Halachah 4; Hichot Pesulei HaMukdashim 19:11.

The rationale is that since the greater portion of the animal emerged, it is considered as "born" and thus the offspring is considered as the firstborn.

Here, also, the Rambam’s ruling is quoted by the Shulchan Aruch, foe. cit., while the Tur and the Rama follow the opinion of Rabbenu Asher who maintains that the offspring’s limbs are not consecrated retroactively. Since they were not consecrated at the time they emerged, their status remains the same afterwards.

Rav Yosef Corcus explains that this is speaking about a situation where the third of the animal that emerges first is cut off from the remainder of the animal.

And thus the greater portion of the animal did emerge.

When the second third of the offspring emerges, the greater part of the animal is present before us. Hence it is considered as if it emerged at one time and hence, becomes consecrated. Accordingly, the sale of the first third to the gentile is nullified, because retroactively, it is considered as if the owner never possessed the third he sold, because it was consecrated property.

Since the first animal is consecrated, the offspring that follow are not considered as firstborn. The Or Sameach and others maintain that this point is obvious and suggest that there is a printing error in the Mishneh Torah and this clause was moved from its proper place.
The Shulchan Aruch, loc. cit.:2, quotes the Rambam’s ruling. The Tur and the Rama follow the opinion of Rabbenu Asher who maintains that the offspring is not consecrated retroactively and the sale to the gentile is binding.

As stated in Chapter 2, Halachah 4, if an offspring is removed by Caesarian section, neither it, nor the offspring that follows it is bound by the laws applying to a firstborn.

I.e., of the first 51 percent of the animal to emerge, the larger portion did not emerge from the womb.

I.e., when the second third emerged, it would have been joined with the first third to make up the larger portion of the offspring. Since the larger portion of the first half of the offspring is not fit to be considered a firstborn, the animal is not granted that distinction.
The Or Sameach maintains that the phrase “[the future offspring of the mother] is exempted from [the requirements of] the firstborn” should be placed here. Even though this offspring is not consecrated, the one which follows is exempt.
In this instance as well, the Shulchan Aruch, loc. cit.:3, quotes the Rambam’s ruling. The Tur and the Rama again follow the opinion of Rabbenu Asher who maintains that the offspring is consecrated (because its larger portion emerged through the womb).

Chulin 70a discusses this instance, explaining that we are speaking about a situation where 47% of the offspring emerged from the womb together with this portion of the limb which constituted a third of the limb, but 5% of the offspring. Hence if the portion is added together with the 47%, the greater portion of the offspring will have emerged from the womb. Hence the animal is considered as a firstborn that died, as in the final clause of Halachah 14. Even though the limb from which this smaller portion is separated remains within the mother animal and emerges afterwards, the smaller portion of the limb is counted as part of the portion that emerged and not as part of the limb that remains.

For it is consecrated as a firstborn. It may not be sold to a gentile or fed to the dogs (Shulchan Aruch, loc. cit.:4).

The unresolved doubt is whether the portion of the limb that remains within the mother animal is considered as part of the limb that emerged (and thus it would be considered as if the greater portion of the offspring emerged) or whether it is considered as part of the animal that remained inside the womb.

And is governed by the laws stated in Halachah 7.

All these questions revolve around the same issue: Must the firstborn touch the mother’s womb as it emerges or is it sufficient for it to emerge from the womb to receive that status? Each of the successive instances brought up by the Rambam represents a further question: the fiber mentioned in the first clause is not flesh, while the placenta is. Hence one could apply the principle (Bechorot 9a, et al): “One entity is not considered as an intervening substance for another entity of that type.” And if one would say that it is inappropriate to apply that principle with regard to the placenta, seemingly, it would be appropriate to do so with regard to the sister, for it is certainly “of the same kind” as the firstborn.
The mother animal’s next offspring is certainly not a firstborn, because this offspring is certainly no worse than an offspring born through Caesarian section.

To enable the firstborn to enter.

And in this instance, it didn’t.

In which instance, it would be consecrated.

In this instance, Chulin 70a does not mention any doubt regarding the matter. Since the walls of the womb are no longer supportive, it is as if the offspring emerged through Caesarian section.

Rashi explains that the question is: Since the portion of the womb that remains is greater than the portion stripped away, is it considered as if the offspring emerged through the womb even though it emerged through the portion that was open?

Here the question is the reverse: Since the portion of the womb that is stripped a way is greater than the portion that remains perhaps it is not considered as if the offspring emerged through the womb even though it emerged through the portion that remains (ibid.)?