1) HALACHAH: AN "EIGHTH-MONTH" BABY
QUESTION: The Beraisa states that a baby born after eight months of gestation is not considered to be viable, and therefore it is Muktzah and forbidden to be handled on Shabbos. Does this Halachah apply today?
ANSWER: TOSFOS (DH Ben Shemonah) writes that this Halachah does not apply today for two reasons. First, we are not knowledgeable enough to know whether the baby was born after eight months or after nine months of gestation. The Halachah is that when we are in doubt whether a baby was born after eight months or nine months, we treat him like a ninth-month baby.
Second, even if we would know for certain that the baby was born after eight months, the Gemara in Yevamos (80b) teaches that the baby is not considered viable only when its hair and fingernails are not completely developed (a sign that the baby is not physically complete). If the baby is clearly fully developed, even if it is born after eight months it is considered to be alive. It is viewed as "a seventh-month baby that was born in the eighth month" after tarrying a few days inside the womb. Therefore, a baby born even in the eighth month is considered to be alive unless it is obviously not fully developed.
HALACHAH: This is the ruling of the SHULCHAN ARUCH (OC 330:7-8). Only when a baby born after eight months has obvious signs of incomplete development is it forbidden to be handled on Shabbos. (See Mishnah Berurah 330:30, who cites a different view in the name of the Vilna Ga'on.)
2) HALACHAH: A CONVERT WHO WAS ALREADY CIRCUMCISED AND A BABY BORN CIRCUMCISED
OPINIONS: The Gemara discusses the requirement to perform Hatafas Dam Bris for a person who was circumcised while he was a Nochri, before he converted, and for a baby who was born with no Orlah.
What is the Halachah in these cases?
(a) TOSFOS (DH Lo Nechleku) writes that it appears logical that in both cases, Hatafas Dam Bris is not necessary. He bases this ruling on the words of Rav, who argues with Shmuel and says that the Halachah follows the Tana Kama's version of Beis Hillel's opinion. According to the Tana Kama, Beis Hillel says that a baby born circumcised does not need Hatafas Dam Bris. Consequently, a convert certainly does not need Hatafas Dam Bris, because the requirement of Hatafah for a baby is more strict than the requirement of Hatafah for a convert. (This hierarchy is evident from the Gemara, which says that even according to the opinion that maintains that a baby born circumcised needs Hatafah, a convert does not need Hatafah.)
(b) The BEHAG writes that a baby born with no Orlah does not need Hatafas Dam Bris, as Tosfos says, because we follow the ruling of Rav. However, a convert who was already circumcised does require Hatafah. The Behag bases his ruling on the Gemara in Yevamos (46b). This ruling seems to contradict the logic of the Gemara here, which implies that a convert needs Hatafah to a lesser degree than a baby born with no Orlah.
Tosfos, in the name of Rabeinu Shimshon, explains that logically, Hatafas Dam Bris should be necessary for both a circumcised Nochri who converts and a baby born with no Orlah. However, the Tana Kama derives from the word "Orlaso" in the verse that not only is Hatafas Dam Bris not performed on Shabbos (as the Gemara earlier says), but it is not required at all for a baby with no Orlah. However, that verse refers only to a baby, and not to a convert. Therefore, with regard to a convert, the logic that Hatafah is required remains.
The logic behind this distinction between a baby and a convert may be as follows. The convert may need Hatafah because he was born with an Orlah. The Torah considers someone who was born with an Orlah to be someone to whom Milah can be performed. Therefore, even if he decides to become Jewish after he cut off the Orlah, he is obligated to do some action of Bris Milah, just as the person who still has an Orlah must do. This obligation is fulfilled by Hatafas Dam Bris (ROSH).
Another suggestion (TOSFOS YESHANIM to Yevamos 46b, #4) is that the convert must perform some sort of action to show that he is entering Hash-m's covenant, while a baby born with no Orlah is already a full-fledged Jew, even without the fulfillment of an act of Milah. Since he has no Orlah, he does not need to perform an act of circumcision.
(c) Tosfos here and in Yevamos (46b, DH d'Rebbi Yosi) cites RABEINU CHANANEL who proposes the opposite ruling to that of the Behag. He rules that a Jewish baby born with no Orlah must have Hatafas Dam Bris, but a convert who is already circumcised does not need Hatafas Dam Bris.
From the that Tosfos quotes his words, it seems that Rabeinu Chananel maintains that such a convert becomes a full-fledged Jew with Tevilah and acceptance of the Mitzvos alone (like a woman convert). Indeed, Tosfos in Yevamos (ibid.) mentions that it is logical that a convert who physically cannot perform Milah (because his body is maimed, for example) is accepted as a full-fledged convert without Milah. However, according to the words of Rabeinu Chananel as they appear in our text of his commentary (on 135b; a few words seem to be missing in the version printed in the Vilna Shas), and as cited by the RAMBAN and other Rishonim (see also TUR YD 268), Rabeinu Chananel maintains that because there is no Hatafas Dam Bris for a convert, a Nochri who is already circumcised cannot become a convert at all. (Rabeinu Chananel enigmatically adds that although his conversion does not entitle him to become accepted as a Jew, nevertheless children born to him afterwards are Jews.) None of the Rishonim concur with him in this regard.
(d) The RIF and RAMBAM (Hilchos Milah 1:7) rule that both a Nochri who was circumcised and a baby born with no Orlah need Hatafas Dam Bris. The KESEF MISHNEH explains that this ruling is based on the opinion of Rebbi Eliezer ha'Kafar who says that Beis Hillel maintains that both need Hatafas Dam Bris.
However, the Rambam (Hilchos Milah 3:6) rules that no blessing is recited when Hatafah is performed to the convert. If the Rambam rules like Rebbi Eliezer ha'Kafar, why should one not recite a blessing?
The RAN (on the Rif) explains that the Rambam does not categorically rule like Rebbi Eliezer ha'Kafar. Rather, the Rambam is in doubt whom the Halachah follows. Therefore, he rules that a convert needs Hatafah out of doubt, but no blessing is recited.
HALACHAH: The SHULCHAN ARUCH (YD 266:4) rules that a baby born with no Orlah needs Hatafas Dam Bris. The SHACH writes that no blessing is recited unless there seems to be some tightly pressed Orlah that is difficult to discern. Similarly, with regard to a convert, the Shulchan Aruch (YD 268:1) rules like the Rambam that a convert needs Hatafah but no blessing is recited.