In this lesson we will learn Mishnah 6 of the thirteenth chapter of Maseches Yevamos. The Mishnah deals with a woman who was divorced by her husband, was remarried by him, and afterward he died: does she come to yibum from the first marriage, which ended in divorce, or from the second marriage, which ended in death?
"HaMegaresh es haishah v'hechezirah":
The Mishnah opens: "HaMegaresh es haishah v'hechezirah - muteres layavam" - a man divorced his wife and then took her back and married her a second time, and in the meantime she was not married to anyone else, and afterward he died. The Mishnah rules that she is permitted to the yavam.
Why would we have thought that she should be forbidden?
At the moment he divorced her she became the divorcee of the yavam's brother, and one might have said that the prohibition that took effect upon her at that moment remains in place. According to this approach, even though he took her back and afterward died, we view her as coming to yibum from the first marriage - a marriage that ended in divorce and not in death - and therefore she would be forbidden to the yavam.
The Mishnah comes to teach that this is not so: she comes to yibum from the second marriage, and that marriage did not end in divorce but in the husband's death. Therefore she is obligated in yibum and permitted to the yavam.
The view of Rabbi Eliezer:
The Mishnah continues: "Rabbi Eliezer oser" - Rabbi Eliezer forbids. Rabbi Eliezer's reason is not that he holds she comes to yibum from the first marriage; rather, it is a decree, on account of the case brought at the end of the Mishnah.
That case speaks of a minor girl whom her father married off, so that her kiddushin is valid on a Torah level, and who was then divorced from that marriage. From that moment on her father no longer has the power to marry her off, and when she marries again while still a minor - even to that same man - that marriage is only rabbinic, since the father is not involved in it. The result is that on a Torah level only the first marriage exists, and that marriage ended in divorce, and therefore she is forbidden to the yavam.
In this case everyone agrees, including the first Tanna mentioned above, that she is forbidden to the yavam. Because of that case, Rabbi Eliezer issued a decree and forbade even in the case before us, which does not speak of a minor.
"V'chein hamegaresh es hayesomah":
The Mishnah continues: "V'chein hamegaresh es hayesomah v'hechezirah - muteres layavam" - and so too one who divorces an orphan girl and takes her back, she is permitted to the yavam. This orphan was not married off by her father but by her brother or her mother, so her kiddushin is rabbinic, and she was divorced from that marriage. That same man then took her back - she is permitted to the yavam, for we view her as coming to yibum from the second marriage.
The reason: both marriages stand on the very same level, rabbinic kiddushin, and therefore we can say that she comes to yibum from the second marriage, which did not end in divorce but in death.
Here too "Rabbi Eliezer oser" - Rabbi Eliezer forbids, for the same reason: a decree on account of the following case.
"Ketanah shehisi'ah aviha v'nisgarshah":
"Ketanah shehisi'ah aviha v'nisgarshah - kiyesomah b'chayei ha'av" - a minor girl whom her father married off and who was then divorced is like an orphan in her father's lifetime. When a father marries off his minor daughter, her marriage is valid on a Torah level. Once she has been divorced from her husband, she is called "an orphan in her father's lifetime," since her father no longer has the power to marry her off after she has already been married, and the authority has left his hands.
Therefore, when that same husband took her back, the remarriage is only rabbinic. Consequently, all agree - both the first Tanna and Rabbi Eliezer - that she is forbidden to the yavam, since on a Torah level she is nothing more than his brother's divorcee, and she is not a brother's wife who is obligated in yibum.
And on account of this case, in which everyone agrees, Rabbi Eliezer said that in the other cases as well she is forbidden to the yavam. The first Tanna, in contrast, held that we do not issue such a decree.
In summary: this Mishnah deals with the question of which marriage brings the woman to yibum, and it presents three cases:
One who divorces his wife and takes her back: she is permitted to the yavam, since she comes to yibum from the second marriage, which ended in death and not in divorce. Rabbi Eliezer forbids on the strength of a decree.
One who divorces an orphan girl and takes her back: both marriages are rabbinic kiddushin and stand on one level, and therefore she is permitted to the yavam. Rabbi Eliezer forbids for the same reason.
A minor girl whom her father married off, who was divorced and then taken back: the first marriage is on a Torah level and the second is only rabbinic, and therefore all agree that she is forbidden to the yavam.
The basis of the dispute, then, is the question of whether we issue a decree in cases that have no inherent flaw, on account of that case in which everyone agrees.