The Mishna (72b) offered two cases where a husband stipulates a condition before marriage. In one, he makes the marriage conditional on the fact that his wife has not taken vows upon herself; in the other his condition is that she does not have any blemishes.
The baraita brought by the Gemara on our daf discusses a woman who accepted these conditions, and following the kiddushin goes to the Sage to have her vows rescinded or to a doctor to have her blemish healed. In such cases, the condition will be considered to have been fulfilled when the vows were removed by the Sage, but not when the blemish was healed by the doctor. In explaining the difference between vows and blemishes, the Gemara explains that the Sage voids the vow retroactively, and we discover that at the moment of marriage the wife really was unburdened by vows. In the case of the doctor, however, the blemish was only healed from the time that the medical procedure was performed, so at the moment that the kiddushin was to take effect, the condition was not fulfilled.
The Re’ah raises a question based on the understanding that a Sage voids a woman’s vows retroactively. If this is the case, how can we ever be certain that the condition upon which the marriage was based was not fulfilled? Is it not possible that the woman – working with the assumption that her vows keep the marriage from being valid – will go and marry another man? In such a case, should she later approach a Sage and have her vows voided she will discover that her marriage to her first suitor was valid, and that she has been living in sin all these years, and that her children from the second man will be mamzerim!
Although this issue is not raised in our Gemara, the Talmud Yerushalmi discusses it and suggests that the fact that the woman did not choose to arrange for her vows to be voided at the earlier opportunity shows conclusively that she was not interested in that marriage, effectively ending it. Nevertheless, another opinion in the Yerushalmi suggests that this is a concern. Due to this question, the Re’ah and his students conclude that a woman in a case like this one will be required to accept a divorce, so that she will be protected from any future concerns.