Back on Nedarim 20, we encountered a mishnah that described four types of vows that can be automatically dissolved without a halakhic authority: vows of exhortation (“come to lunch or I swear I won’t eat a bite today”), vows of exaggeration (“I swear the fish was this big!”), vows made unintentionally, and vows that cannot be fulfilled due to circumstances beyond one’s control. These are vows made in a moment of passion, a moment of disorientation, or without a complete understanding of the circumstances — all of which, the rabbis reasoned, a person ought to be allowed to dissolve on their own. This leniency would hopefully prevent a great deal of needless sinning — which, in a nutshell, is the primary concern of this entire tractate.
Even more powerful than allowing people to dissolve their own vows post-facto is enabling them to proactively annul them. This idea appears in a mishnah at the bottom of yesterday’s daf which kicks off a discussion that will spill onto our page. Here’s the mishnah:
Rabbi Eliezer ben Ya’akov says: Even one who wants to take a vow in order that his friend should eat with him should say to (his friend): Any vow that I take in the future is void. And this only works if he remembers at the time of the vow.
Rabbi Eliezer ben Ya’akov is talking about a vow of exhortation — a vow made, in this case, to compel a friend to join you for lunch. Such vows, as we have learned, can be nullified without rabbinic assistance. But Rabbi Eliezer suggests that it is better not to rely on post-facto nullification and instead perform a preemptive nullification by explicitly telling this friend that future vows are void. This way, the would-be host can pull out all the rhetorical stops without fear of accidentally transgressing a vow — provided he actively remembers that he did that preemptive nullification.
The Gemara now points out that proactively annulling your vows and then making one anyway might ruin the rhetorical effect. Hey, Joe, my vows are void. Also, I swear I will not eat at all if you do not join me for lunch. It just doesn’t pack a punch.
Therefore, says the Gemara, we need to understand that the mishnah means something else:
The mishnah is incomplete and is teaching as follows: One who wants another to eat with him, and he urges him and makes a vow with regard to him, this vow is a vow of exhortation. Further, one who desires that his vows not be upheld for the entire year should stand up on Rosh Hashanah and say: Any vow that I take in the future should be void. And this is effective, provided that he remembers at the time of the vow.
In other words, the prospective lunch host doesn’t need to nullify his vow ahead of time because it is a vow of exhortation and he can always nullify it later. But it is also possible to make a blanket nullification of vows on Rosh Hashanah that is effective for an entire year.
Sound familiar? If you were in synagogue on Erev Yom Kippur this year, you likely did this at services. In fact, the Erev Yom Kippur Service is named for the Kol Nidre (“All the Vows”) prayer, traditionally recited in the last moments before Yom Kippur begins, which does exactly what the Gemara proposes: It nullifies all vows we will make in the coming year. And it really works, says the Gemara, as long as you remember you did it. (Kol Nidre was moved from Rosh Hashanah to Erev Yom Kippur because, even 1,000 years ago, that service was better attended.)
If you didn’t know this was the point of Kol Nidre, that might not be an accident. Reading on, we see that the rabbis were ambivalent about telling people what this prayer was really about. The Gemara explains that Rav Huna bar Hinnana would make public lectures ahead of Rosh Hashanah — lectures for all Jews, not just rabbinic disciples — in which he explained the procedure of preemptively annulling vows. But Rav Huna’s colleagues were uncomfortable with this, pointing out that the mishnah itself is not explicit about the blanket, year-long nullification. Rava explains why:
The Tanna of the mishnah conceals it in order that the public not treat vows lightly.
As historians, we might speculate that the mishnah makes no mention of collectively annulling vows for a full year because the practice had not yet developed. But Rava says that the mishnah knows of the practice and conceals it so as not to give people the impression that vows are insignificant.
It seems that it was difficult to get people to accept the full gravity of vows. The rabbis wanted people to annul their vows on Rosh Hashanah so they did not spend the year making vows and then transgressing them — suggesting, of course, they were not taking vows as seriously as the rabbis would have liked. But they also did not want to make a big show of annulling a full years’ worth of vows on Rosh Hashanah, because that too might give people the impression that vowing is not serious. Underlying this whole discussion, and much else in this tractate, is this very dilemma: Vows might feel insubstantial, but they are actually quite dangerous because they can be so easily transgressed and lead to sin. How can we convince people to take them seriously?
Read all of Nedarim 24 on Sefaria.