Introduction to Yevamot
The laws of levirate marriage are contained in Deuteronomy 25:5-10. According to these laws, if a husband dies without children, his brother should marry his widow and the first son that she bears shall be accounted to the dead brother. This is in order for the dead brothers genealogical line to be continued. If the live brother refuses to marry his dead brothers widow, she performs a ceremony known in the Mishnah as halitzah. This entails her taking off his shoe and spitting in his face (the rabbis understand this to mean spitting on the ground). After halitzah, the woman can marry whomever she chooses, as can a normal widow.
There are two instances of levirate marriage in the Tanakh, one involving Judahs sons and daughter-in-law (Genesis 38) and one involving Ruth and Boaz (see Ruth 3:12 and chapter 4). Some of the legal details of these instances do not match those of Deuteronomy. It is sufficient to note that the rabbis follow the laws of Deuteronomy and do not derive the laws of levirate marriage from Genesis or Ruth.
There are a few rules that we should explain here in the introduction, in order to make the learning of this sometimes difficult tractate simpler. First of all, a woman whose husband has died without children is forbidden to marry another man until she has levirate marriage or halitzah. Second, a man may not perform levirate marriage for a woman who is forbidden to him. For instance, if two brothers marry two sisters and one dies, the widow is not subject to the laws of levirate marriage, because her sister is married to the levir (a man cannot marry two sisters). Third, both betrothed women and married women are subject to the laws of levirate marriage. Fourth, levirate marriage is obligatory only for paternal brothers.
There is some debate in the Talmud whether or not levirate marriage is currently preferable to halitzah. In post-Talmudic times, Ashkenazim held that halitzah was mandatory and they abolished levirate marriage. Certain Sephardi groups continued to practice levirate marriage until the formation of the State of Israel, which has adopted the Ashkenazi position. Much of these differences can be attributed to the fact that Ashkenazim banned bigamy, while most Sephardim did not.
The following is a list of Hebrew terms and their meaning. I will use these terms in transliteration because they are less cumbersome. I suggest you print this page so that you can reference it while we learn the tractate.
Halitzahrelease from levirate marriage.
Halutzaha woman who has performed halitzah. A priest cannot marry a halutzah.
Maamarthe giving of money from the yavam to the yavamah, a parallel to the betrothal money given as kiddushin in normal marriages. According to the Torah there is no marital process for the widow who goes through yibbum. All that really happens is that he has relations with her, and thus yibbum is performed. However, the rabbis created an institution called maamar whereby the yavam would give her betrothal money similar to the betrothal money given in regular marriages (we will learn these laws in tractate Kiddushin). Maamar, however, does not make the woman the yavams full wife. The status of their marriage is only rabbinic. This will have many important implications in certain mishnayoth.
Mamzerthe child of an illicit union or the child of a mamzer. The Torah states, A mamzer shall not be admitted into the congregation of the Lord (Deuteronomy 23:3). We will see in the mishnah that there are several different opinions as to which type of illicit union creates a mamzer. A mamzer cannot marry a regular Israelite. I will not translate mamzer as bastard, as it is often translated, because in American lingo a bastard is also the child of an unmarried couple. This is untrue in Jewish law.
Shomereth yavam (yavamah)a woman who is subject to the laws of levirate marriage (i.e. her husband died without children).
Yavamthe living brother (there may be more than one, if the dead brother had two or more brothers.) In English he is called the levir.
Zkukaha woman with whom he is liable to have yibbum or halitzah, but with whom he has not yet done so. The word zkukah comes from the word zikah which means tied to or bound. A zkukah is bound to the yavam until halitzah or yibbum (then she is bound as a regular wife is to her husband).
The first few chapters of Yevamot are extremely complex. In order to make things simpler I will use names, generally Biblical one. Please dont despair if you get lost. Once the principles become clear, most of the rest is just details.