Yevamot 86 - 92
Prohibition or Nullification
- Yevamot 92b
The prohibition against a yivamah marrying an outsider is phrased in a manner that lends itself to two interpretations.
"The wife of the deceased" says the Torah (Devarim 25:5) "shall not be married outside the family to a stranger."
The interpretation of the Sage Rav is that this is the Torah's way of saying that any marriage with an outsider will be null and void with no divorce required to end it. Although the general rule, according to the majority position of the Sages, is that a marriage forbidden by a prohibition punishable only by lashes is considered as having force and requiring a divorce to end it, an outsider marrying a yivamah is an exception.
This position is disputed by the Sage Shmuel who rules that such a marriage may indeed have force and that a divorce is required to end it. The explanation of his position is that he is in doubt as to whether the words "shall not be married" are to be understood like Rav's position that this is a nullification of the force of such a marriage or merely a prohibition against such a marriage which would leave it in the general category of forbidden marriages which are in force and require a divorce.
Tosefot (Yevamot 49b) points out that, contrary to the impression gained from the words of Rashi, Rav agrees that there is definitely a prohibition against a yivamah marrying an outsider but the phrasing of the prohibition also indicates that such a marriage has no force and requires no divorce.