In contrast to “normal” marriage, levirate marriage is marked by irregularities and complexities. Speaking broadly, a levirate union involves a widow and a male from the family of her deceased husband; in Jewish tradition, the only man required or permitted to enter into a levirate marriage is the brother of the deceased. The offspring of a levirate union are usually recognized as the legal offspring of the woman’s late husband, rather than the offspring of their biological father, who is known as the levir. Although in many cultures, levirate unions are not regarded as marriages, postbiblical Judaism treats the union of a man and his brother’s widow as a marriage. This construct of marriage creates anomalies within the broader construct of Jewish marriage. The first and most troubling anomaly created by the institution of levirate marriage lies in the relationship between the levir and the widow before their marriage. Jewish law has myriad rules restricting an individual’s choice of a marriage partner; many of these rules prohibit marriage between close relatives. Among the incestuous unions forbidden in Leviticus 18 and 20 is the prohibition against a sexual relationship between a man and his brother’s wife. This prohibition is understood by ancient commentators to apply even if the woman in question becomes a divorcée or a widow.

Levirate marriage by definition, however, requires a man to marry his brother’s widow and, if the goal of levirate—the birth of a child who will carry on the name of the deceased—is to be fulfilled, he must have sexual relations with her. Thus levirate becomes a permitted (or even mandated) incest. This problem is noted by early rabbinic sources. Noting the apparent contradiction between Leviticus 18:16 and Deuteronomy 25:5, midrashim claim the two verses were “spoken at the same moment,” that is, God knowingly gave two laws that seem to be in opposition but that can in fact co-exist. The law of levirate serves as an exception to the incest prohibition or overrides it. At the same time, the Mishnah begins its discussion of levirate marriage by prohibiting marriage between a levir and his widowed sister-in-law if the latter would be forbidden to him under any incest prohibition other than that of a brother’s wife. Moreover, the Mishnah extends the prohibition to all of the wives of the deceased brother if even one of them is forbidden to the levir for reasons of consanguinity. These texts suggest that the rabbis, realizing that any levirate marriage may be perceived as “permitted incest,” simultaneously reassured themselves that levirate is not incest while prohibiting levirate unions in which there had been multiple family ties between the levir and the widow.

The other significant anomaly that distinguishes levirate unions from non-levirate marriage is the assignment of the offspring of the union to the mother’s deceased husband rather than the levir. Genesis 38, the story of Judah and Tamar, offers evidence that this aspect of levirate may have been disturbing to potential levirs. Onan is reluctant to impregnate Tamar knowing that any child born to her “would not be his,” but that of his late brother, Er. According to Deuteronomy, the birth of a child who can “be accounted” to the deceased, “that his name may not be blotted out in Israel” is the aim of levirate marriage. Rabbinic tradition supports the notion that this is the primary if not the sole aim of levirate by declaring that levirate marriage is not performed if the deceased left any child or grandchild. At the same time, rabbinic law upends the aim of levirate marriage, declaring that the children of such a marriage are treated under the law as the offspring of their biological father, the levir. Beyond a rather tortured exegesis on Deuteronomy 25:6, rabbinic literature offers no explanation for this innovation.

Another difference between levirate marriage and other marriages lies in the way it is contracted. Rabbinic law requires that a man betroth his future wife and that she consent to the betrothal. A levirate widow, in contrast, is bound to her husband’s brother from the moment of her husband’s death; betrothal is not, strictly speaking, required. Moreover, since the bond between them is generated by the husband’s death, the widow’s consent is not necessary. A levirate marriage is brought into being through an act of intercourse, even, according to the Mishnah, if the act is casual or nonconsensual. We do have sources that mandate a speech act (ma’amar) on the part of the levir and the widow’s consent as part of the process of formalizing a levirate union, suggesting the desire on the part of at least some rabbis to “regularize” levirate unions by making them more like other marriages.

Faced with a biblical law that promotes a distinctly irregular form of marriage, the rabbis of the first five centuries of the Common Era sought to smooth out many of the anomalies present in levirate unions. The rabbis’ efforts to “normalize” levirate marriage offer us insights into the way they understood the family and familial relationships. Every marriage creates a new family and reorganizes several others. Men and women become husbands and wives, entering into new relationships with individuals who were previously “strangers.” Parents and siblings become in-laws. Families that were previously distinct and separate entities become intertwined. In some cases, families experience the marriage of a family member as a “loss” to the family; in others, marriage is seen as a way in which the family “gains” new members. Levirate marriage offers a fascinating glimpse into constructs of family because it involves two individuals who were already related but who are now entering a very different type of relationship; the levir and the widow make the transition from a close family relationship in which they are forbidden to think of each other as potential mates to one in which they are expected to become husband and wife. Additionally, the opportunity for levirate marriage arises from a family crisis, the death of a husband and brother. The death “disorders” the family, leaving the childless widow with no tangible connection to her late husband’s family. Levirate offers a path to reordering the family, reintegrating the widow into her husband’s family through marriage to his brother. At the same time, a family unit that is disrupted by death cannot be wholly repaired, nor can it be restored to its previous state. In many cultures, levirate is an attempt to provide a widow with a socially acceptable sexual outlet while discouraging or prohibiting remarriage and at the same time providing the deceased with children after his death. On some level, the deceased remains a strong presence in his family; his wife, while permitted a sexual relationship with one of her husband’s relatives, remains “faithful” to her husband by not remarrying; the children born to her are legally his children. Rabbinic Judaism chose a different path; it chose to privilege the claims of the living over those of the dead.

The levir is not his brother’s surrogate; he is a husband. The widow ceases to be a widow and becomes the wife of a second husband. The children born of this union are the legal offspring of their biological father. From the ruins of one nuclear family, levirate marriage creates a new one. It does so by “renaming” individuals or reassigning roles, transforming brother-in-law and sister-in-law into husband and wife. This legal transformation is not magical. Literature from many cultures indicates that levirate unions could be emotionally and socially problematic for the individuals involved. Nevertheless, rabbinic understandings of levirate marriage mark an attempt to regularize the irregular and to place individual men and women into relationships that reflect rabbinic visions of “normal” marriage.