Study Yevamot folio 15A with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
Text Excerpt
שיהו חולצות ולא מתייבמות. לא הספיקו לגמור את הדבר עד שנטרפה השעה.
that they should perform ḥalitza and not enter into levirate marriage. If they act in this manner, they will be permitted to marry others and the problem will be solved according to all opinions. They were unable to finalize the matter according to the proposition raised by R' Yoḥanan ben Nuri before times of trouble arrived. Due to the outbreak of war they were unable to gather together to vote and establish an accepted halakhic ruling.
אמר ליה רבן שמעון בן גמליאל: מה נעשה להם לצרות הראשונות מעתה?
Sometime later, when they returned to discuss the issue, Rabban Shimon ben Gamliel said to the other rabbis: What should we do with those earlier rival wives from now onward? Since in the meantime some rival wives had entered into levirate marriage, if we issue a collective ruling that rival wives may not do so, their children will be declared mamzerim. Therefore, it is better not to establish this halakha at all.
אי אמרת בשלמא עשו — היינו דקאמר מה נעשה. אלא אי אמרת לא עשו, מאי מה נעשה?
The Talmud analyzes this episode in relation to the matter at hand. Granted, if you say that Beit Shammai did act in accordance with their own opinion, this is the meaning of what Rabban Shimon ben Gamliel said: What should we do? Since these rival wives had already entered into levirate marriage, it was impossible to change the status of their children retroactively. However, if you say that they did not act in accordance with their opinion, what is the meaning of: What should we do? If Beit Shammai did not act upon their ruling, they never actually permitted a yavam to take a rival wife in levirate marriage.