Commentary for Bava Kamma 5:4

An ox that was intending for his friend and struck etc....

שור שהיה מתכוון לחבירו וכו' – since our Mishnah had to teach the “concluding” (actually, the next phrase) part [of the Mishnah] that a person who intended [to strike] his fellow, the first part [of the Mishnah] teaches also regarding an ox that intends [to gore] its fellow [ox], for even if it had intended [to gore] a woman , the [owner of the] ox is exempt from the payment [for the value of] the offspring, for he is not liable for the payment [for the value of] offspring other than of a human being alone.

If an ox intended [to gore] another ox and struck a woman and her offspring came forth [as a miscarriage], its owner is not liable for the value of the offspring. But if a man intended to strike his fellow and struck a woman and her offspring came forth [as a miscarriage], he must pay the value of the offspring.
How does he pay the value of the offspring? They assess the value of the woman before she gave birth and the value after she gave birth.
Rabban Shimon ben Gamaliel said: “If so, once a woman gives birth she is more valuable. Rather, they assess how much the offspring would be worth, and he pays it to the husband, or if she has no husband to his heirs.”
If she was a freed bondwoman or a proselyte no penalty is incurred.
Exodus 21:22 states: “When men fight, and one of them pushes a pregnant woman and a miscarriage results, but no other damage ensues, the one responsible shall be fined according as the woman’s husband may exact from him, the payment is to be based on reckoning” (JPS translation). According to the Torah, usually a person who accidentally kills another person cannot pay in order to atone for his crime. However, in the case described in this verse the person did not kill an independent human being but rather he caused a miscarriage. Therefore the Torah allows him to make financial compensation for the loss of the fetus/baby. (I am attempting to be very careful about the sensitive issue of Judaism’s stance on the status of a fetus and on abortion. One could potentially argue from this verse that according to the Torah a fetus is not equal to a born human being. However, an exemption from murder charges for one who accidentally causes a miscarriage is not necessarily a blanket approval for abortion.)
Our mishnah deals with two subjects. The first is a definition of the scenario in which this law will apply. The second is an account of the payments required for causing the miscarriage.
Section one limits the application of the verse from Exodus to a case where a person caused a miscarriage. After all the verse states, “When men fight…” and therefore it can be assumed that the law does not apply when an ox causes the miscarriage. In this case the owner of the ox will pay for the damage done to the woman and not for the damage done to the offspring.
Section two begins a discussion of the payments made for the miscarriage. According to the first opinion one evaluates the worth of the woman before the pregnancy and after the pregnancy and the difference is the payment for the offspring. This payment is made to the husband, as we shall learn in section 3a. The payment for the damages to the woman herself is a payment to the woman and the payment for the loss of the offspring is a payment to her husband. According to Rabban Shimon ben Gamaliel (section three), a pregnant woman is actually worth less than a non-pregnant woman. In order to understand his words we must remember that in those times death during childbirth was all too common. A pregnant woman was in a dangerous situation and therefore her value is lower. Once she gives birth her value will rise because she is out of the dangerous situation. Therefore, we cannot use this system to evaluate the payments. Rather, according to Rabban Shimon ben Gamaliel, we estimate how much the offspring themselves would have been worth.
In section 3a we learn that if the woman’s husband died between the time of conception and the time of the miscarriage, the payments are an inheritance to his inheritors. Section 4 is concerned with two women whose husbands are likely not to have inheritors. There are two possibilities to understand this section. First of all, if a woman is a bondwoman and is freed while pregnant, or a woman converts while pregnant, her husband or impregnator is no longer legally responsible or legally considered the father of the children. Therefore, if someone should accidentally cause her to miscarry, there is no father that can collect the payment. Alternatively this last section may deal with a freed bondwoman who marries a freed slave or convert or a convert who marries another convert. The miscarriage occurs after this husband has died and before they have other children. In this case the husband has no inheritors since converts and freed slaves do not have inheritors in their families from before they changed their status.

Because it wants to discuss that if a man is intending (to strike) his friend, it says an ox who intends (to strike) his friend, and there's no difference whether the ox intended for an ox and struck a woman or he intended to the woman herself, he is not obligated the value of the fetus since the torah does not obligate in this, rather a man only. And what that it says with a convert, that he is exempt for the fetus, does not mean to say that when she converted that she was already pregnant, as this is clear to us, rather it means to say that she got [pregnant] [SUBSTITUTE: attacked] in the life of (her husband) the convert and the convert died or she miscarried after the death of the convert, because the principle in our hand is when there is a husband, the torah endowed it to him, when there is not it is not endowed to him. Therefore he is not obligated in the value of the fetus when there is not to this convert heirs, meaning to say 'sons' that were born in the jewish religion and their conceiving was when they were jewish. And we already know the words of Rabban Shimeon ben Gamliel, is it true that when a woman for whom she gives birth (her husband), she increases (in value)- and she does not have any portion in the increase of value at all? And this is what Rabban Shimon Ben Gamliel says, yes, the value of the fetuses are to the husband but the value of (the woman, caused by the) fetus is divided. And the Sages say the increase from the pregnancy is to the husband. Therefore the first tanna evaluates the increase (of the woman) and the value (of the fetus) and gives everything to the husband. And in this the gemora explains the words of the first tanna and says how we evaluate the value of the fetus, we evaluate the woman how much she was worth etc... And the halakah is not like Rabban Shimon ben Gamliel.

א"כ משהאשה יולדת משבחת – if so, that this is what we assess just as you said, it is found that he doesn’t give you anything for from when the woman gives birth, her worth is enhanced for her monetary value is less to be sold prior to her giving birth when she is in danger of dying in the pain of childbirth.

היתה שפחה ונשתחררה – meaning to say, when she was freed, she was married to a convert or to a manumitted slave or a female convert is married to one of them , and the husband (who was a freed slave or a convert) passes away, [the owner of the one who caused the damages] is exempt, for the individual who takes possession of the property of the convert who died and he has no heirs has merited, and this comes prior to acquiring what is in his hands. And the same law applies also to an Israelite woman who married a convert, and the convert died, he is exempt, for the value of the offspring goes to the husband, but because an undefined freed woman slave or a female convert are married to a male convert or to a freed slave, for this reason, [the Mishnah] took the language of a maidservant and a female convert.