פירוש על יבמות 9:1

יש מותרות. כהן הדיוט שנשא אלמנה – and the same law applies for a virgin, for when he (i.e., her husband) dies, she becomes a widow. But it (i.e., the Mishnah) took [the term] "אלמנה" /widow – because it needed to teach the concluding clause [of the Mishnah] regarding a High Priest who married a widow.

Introduction The first two mishnayoth of this chapter list variations of women who are either permitted or forbidden to their husbands and to their yevamim (their husband’s brothers). This chapter does not really teach new laws that were unknown from other places in the Yevamoth. Rather it organizes them in a different manner.

Some women are permitted to their husbands and forbidden to their yevamim, Others are permitted to their yevamim and forbidden to their husbands, Others are permitted to both, Others are forbidden to both.
[In all these cases the women] are permitted to their husbands and forbidden to their yevamim. This section is an introduction to this mishnah and the next. The different combinations will be explained as we proceed. Note how formulaic it is and how easy it must have been to remember.

These are the women who are permitted to their husbands and forbidden to their yevamim: An ordinary priest married a widow and had a brother who was a high priest; A halal married a woman who was fit and had a brother of legitimate status; An Israelite married the daughter of an Israelite and had a brother who was a mamzer, A mamzer married a mamzeret and had a brother who was an Israelite. The following cases are ones in which a woman is married to a man to whom she is permitted but should her husband die without children she would not be permitted to have yibbum with the yavam. An ordinary priest who married a widow and had a brother who was a high priest: An ordinary priest is allowed to marry a widow but the high priest may not. A halal who married a woman who was fit [to marry a priest] had a brother of legitimate status: A halal is the child of a priest and a woman who is forbidden to a priest (such as a divorcee). A halal may marry anyone. However, once a woman has relations with a halal, she also becomes a halalah. A halal may have a brother who was not a halal, if, for instance, his father was a priest and his mother was a divorcee and his brother’s mother was fit to marry a priest. In such a case the halal’s wife may not have yibbum with his brother because she is a halalah, and a priest cannot marry a halalah. An Israelite who married the daughter of an Israelite had a brother who was a mamzer: A mamzer may not marry the daughter of an Israelite. Therefore, the mamzer brother of an Israelite may not have yibbum with his dead brother’s wife. An Israelite might have a brother who is a mamzer if, for instance, his father had an affair with another woman while she was married. A mamzer married a mamzeret had a brother who was an Israelite: This is the reverse situation as that which we saw in the previous section.