QUESTION: The Mishnah lists the women who must wait three months after the death (or divorce) of their husbands before they may remarry or do Yibum. The Gemara asks why the Mishnah lists both pairs, "Besulos and Be'ulos" and "Arusos and Nesu'os," when they are the same -- "Besulos" and "Arusos" are the same, and "Be'ulos" and "Nesu'os" are the same. RASHI explains that since the only way in which a woman can be widowed or divorced as a Besulah is when she was only an Arusah to her husband, "Besulos" and "Arusos" are the same.
The Gemara answers that the Mishnah refers only to one pair of cases, "Besulos and Be'ulos." The Mishnah means that both Besulos and Be'ulos -- who are women who became widows either as Arusos or Nesu'os -- must wait three months.
The Gemara's question and answer are difficult to understand.
(a) Why does the Gemara assume in its question that if the woman is a Besulah she must have been only an Arusah to her previous husband? It is possible for a woman to be a Besulah and a Nesu'ah, such as when her husband did not live with her after the Chupah! (ARUCH LA'NER)
(b) Also, the Gemara's answer -- that the words "Arusos and Nesu'os" in the Mishnah are intended as an explanation for the earlier terms "Besulos and Be'ulos" -- is unclear. Why does the Mishnah need to explain "Besulos and Be'ulos"? The Gemara itself assumed in its question that the word "Besulos" must refer to a woman who was only an Arusah. Why does the Mishnah need to explain something which is obvious?
(a) The Gemara understood in its question that even if "Besulos" refers to a Nesu'ah who did not live with her husband after the Chupah, the wording of the Mishnah is still problematic. There is no point in mentioning "Besulos" and "Be'ulos" at all. The Mishnah should have said merely that "Arusos and Nesu'os must wait three months," and all of the women would have been included in that statement.
The Gemara answers that the terms "Arusos and Nesu'os" explain the terms "Besulos and Be'ulos." The term "Besulos" refers to a woman who was an Arusah with her first husband. If she became a Nesu'ah (through Chupah) but did not yet have relations, she is not called a Besulah. Rather, she is in the category of a Be'ulah even though she never had relations.
Why does the Mishnah emphasize this point? What difference does it make if all women must wait three months? The answer is that it makes a difference according to the opinion of Rebbi Yosi and Rebbi Yehudah who maintain that an Arusah (i.e. a Besulah) does not need to wait three months. They will agree that in the case of a Besulah who became a Nesu'ah (through Chupah) and did not have relations, the woman is considered a Be'ulah and must wait three months. (M. Kornfeld)
(b) The MAHARSHA writes that RASHI in Eruvin (47a, DH Achas Besulos) explains the Gemara's answer differently. The Gemara means that the Mishnah requires a woman to wait three months after her second husband dies, whether she was a Besulah or Be'ulah when she married her first husband (who died or divorced her). The Mishnah continues and says that she must wait three months regardless of whether her second husband died (or divorced her) after Erusin or after Nisu'in.
This explanation is more consistent with the words of the Gemara. According to the first explanation for the Gemara (in (a) above), the Gemara should have said explicitly that the second part of the Mishnah "is explaining" the first part -- "Perushei Ka Mefaresh."
However, according to this explanation, why does the woman's status in her first marriage affect whether or not she must wait three months after the end of her second marriage? If she was an Arusah from the second marriage, what difference does it make if she was a Be'ulah from the first marriage? Her status in her first marriage is inconsequential to her status now (i.e. she is certainly not pregnant from her first husband)! (NEHOR SHRAGA)
The answer may be as follows. Had the Mishnah mentioned only Arusos who are Be'ulos from a previous marriage, one would have thought that the Gezeirah requires that only such women wait three months, because people know that Nisu'in was done with one husband and they might confuse the second husband with the first. The Mishnah teaches that even if a woman was a Besulah from both marriages (even from the first), she still must wait three months.