Levirate Marriage and the Family[ ]married to one of this man’s closest relatives. Thus a man could find
himself married to a woman who once shared a home and a husband
with his mother or his sister! He thus marries a woman who was once
married to his stepfather or his brother-in-law.
The rule at Mishnah Yevamot : can be explained by assuming that
the rabbis treat all of a man’s wives as a unit rather than as individuals.
If so, restrictions that applied to one woman might apply to all of them.
This is the case when levirate marriage or halitza occurs; if one of the
deceased’s brothers marries or releases one of his brother’s widows, all
of the others are free to remarry without halitza.^60 A man cannot marry
more than one of his brother’s widows, nor can two surviving brothers
each marry one of their deceased brother’s widows; like the widows,
brothers are treated as a unit vis-à-vis the levirate bond.
Viewing the wives or widows of one man as a unit, however, does not
entirely explain the prohibition against co-wives of a forbidden woman.
If this were the case, a man could not marry the co-wife of the relatives
listed in Mishnah Yevamot :. Co-wives are not treated as a unit un-
less levirate is a possibility. The Bavli specifies the distinction in its ob-
servation that “the [prohibition regarding the] co-wife only applies to a
brother {when the situation involves levirate}.”
Why are co-wives of female relatives permitted to be marriage part-
ners when their former husband is a “stranger,” but forbidden when the
marriage would be a levirate union? I would suggest that it is the rabbis’
concerns about levirate as a type of “permitted incest” that lead them to
forbid co-wives of relatives. The “double” ties between a levirate widow
who is the co-wife of a relative and her levir render them too close — a
man cannot marry a woman who is both his sister-in-law and the co-
wife of his daughter or his wife’s sister, for example. While levirate mar-
riage by definition involves a union between two people who are already
“close,” they should not be too close, lest people view levirate marriage
as incestuous.
The extent to which the rabbis go to downplay the association be-
tween levirate and incest can also be seen in additional restrictions on
lev i rate. In add it ion to forbidd i ng lev i rate ma r r iage bet ween fi rst-deg ree
relatives (erva) and their co-wives, the rabbis also forbid levirate mar-
riage between a man and his secondary relatives (shniyot). Co-wives of
secondary relatives are required to perform halitza, but ca nnot per form