פירוש על בכורות 8:4

שתי נשים – of one man/husband, and they gave birth to two male [children] in a hiding place, that were mixed up.

Two women who had never before given birth gave birth to two males: he [the father] gives ten selas to the priest.
If one of the children dies within thirty days [of its birth], if he gave the redemption money to one priest alone, he returns five selas to him, but if he gave it to two priests, he cannot reclaim the money from them.
If they gave birth to a male and a female or to two males and a female, he gives five selas to the priest.
If they gave birth to two females and a male, or to two males and two females, the priest receives nothing.
If one woman had given birth before and the other had never given birth, and they gave birth to two males, he gives five selas to the priest.
If one of the children died within thirty days [of its birth], the father is exempt.
If the father dies and the sons survive: Rabbi Meir says: if they gave the five sela's before the property was divided up, then what they gave is given; but if not, they are exempt. But Rabbi Judah says: there is a claim on the property.
If they gave birth to a male and a female, the priest receives nothing.
This mishnah deals with a case where two different women gave birth for the first time and their children got mixed up. Note that this mishnah is very similar to the mishnah concerning animals whose first borns are mixed up (see 2:7).
Section one: In this case both children are certainly first born males, so the father must give ten selas to the priest.
Section two: In this case one of the sons dies before he reaches thirty days. The father should have given only five selas to one priest. If he had already given ten selas to one priest, then he can ask for five back. However, if he had given five selas to one priest and five to another, he can’t recover either, because both priests can claim that their money was used to redeem the living son.
Section three: If the two women gave birth to one male and one female, or between them two males and one female, then there is only one child who is certainly a first born male. The other male may be the younger brother of the first born female. Therefore, he only gives five selas to the priest.
Section four: If there are two females and either one or two males, then it is possible that neither male is a first-born, so the priest receives nothing.
Section five: In this case, one child is certainly a first-born and one is certainly not. Therefore, he gives five selas to the priest.
Section six: This is the same debate we saw in section three of yesterday’s mishnah. For reference, see there.
Section seven: If the two give birth one to a male and one to a female, the priest receives nothing because we can’t be sure that there was a first born male.

אם לכהן אחד נתן – for the redemption of both of them, the Kohen would return to him five Selaim, for the one of them (i.e., the babies) died within thirty days [of birth], and the matter was revealed that he was premature/not a viable birth, and that he took [money] not according to the law.

אין יכול להוציא מידם – for each one of them (i.e., the individual Kohanim) can supersede him and say, “I am taking possession of them (i.e., these five Selaim) for the redemption of the living [child].

או שני זכרים ונקבה – his wives gave birth in a hiding place.

נותן חמש סלעים לכהן – whichever way you turn, one of them is a first-born male; if one of the wives gave birth to two male [children], the first one is a first-born, but if one of them gave birth to a male and a female, it is found that her partner gave birth alone to a male, and he is the first born, and the one that is with the female is exempt, perhaps, the female came out first.

אין לכהן כלום – that one is able to say that the girls came out first and there is no first-born male here.

נתנו עד שלא חלקו כו' – as I explained above (in Mishnah 3 of this chapter). And the Halakha is according to Rabbi Yehuda.

זכר ונקבה – one can say that the wife that had not given birth gave birth [first] to a female, and there is no first-born [male].