Nedarim Chapter 3, Mishnah 2. In the previous mishnah we learned that four types of vows do not take effect and are therefore permitted: even though it appears that the person is making a vow, the vow does not take hold at all. Now we will look more closely at two of them - nidrei havai (exaggerated vows) and nidrei shegagos (vows made in error) - and from there we will arrive at the dispute between Beis Shammai and Beis Hillel regarding a vow that was partially annulled.
Nidrei Havai - Exaggerated Vows:
The second of the four categories is nidrei havai, vows stated in the language of exaggeration. The mishnah brings two examples:
"Konam im lo ra'isi baderech hazeh k'yotz'ei Mitzrayim" - a person declares konam, forbidding a certain item to himself, if he did not see on this road as many people as those who left Egypt, six hundred thousand men. This is nothing but sheer exaggeration.
"Im lo ra'isi nachash k'korah shel beis habad" - a person forbids a certain item to himself if he did not see a snake as large as the beam used in an olive press, an exceptionally large object. The Gemara explains that snakes of such a size do in fact exist, and therefore the intent is a snake resembling an olive press beam in its shape and contours - something that does not exist. It emerges that the person is merely exaggerating and has no intention that the vow should take effect.
Nidrei Shegagos - A Vow Made in Error:
The next permitted category is nidrei shegagos, a vow made based on a mistaken understanding of the facts. The mishnah brings several cases:
"Im achalti v'im shasisi" - a person forbids a certain item to himself if he ate or drank at a particular time, and he is convinced that he did not eat or drink. After making the vow he recalls that he did in fact eat or drink at that time. Since he wanted the vow to take effect only on the assumption that he had not eaten or drunk, the vow does not take effect.
"Konam ishti nehenis li shegoneves es kisi, sheh'hikasah es b'ni" - a person makes a vow against his wife that she should not derive benefit from his property, because she stole his purse and because she struck his son. "V'noda shelo hikasu v'noda shelo genavaso" - afterwards it becomes clear to him that she did not strike his son and did not steal his purse. The vow was made in error and does not take effect, since he never intended it to take effect unless the facts were true, and they are not true.
"Ra'ah anashim ochlim te'einim":
Another case: a person sees a group of people eating figs, "v'amar harei aleihem korban" - and he says that they and their property should be forbidden to him like a korban. "V'nimtze'u aviv v'echav" - and afterwards it becomes clear to him that among that group are his father and his brother, "v'hayu imahen acheirim" - and with them were other people as well. It is clear from the circumstances that he had no intention of including his relatives in the vow.
Beis Shammai say: "Hen mutarin ush'ar b'nei adam asurin" - his father and his brother are permitted, since he never intended to include them; but the rest of the people remain forbidden.
Beis Hillel say: "Eilu v'eilu mutarin" - both groups are permitted and the vow does not take effect at all.
The reasoning of Beis Hillel: "Neder shehutar miktzaso hutar kulo" - a vow that was partially annulled is entirely annulled. When a person makes a vow, his intention is that it should take effect in full, and he does not intend it to take effect only halfway. Once it becomes clear that the vow need not apply to part of the group, it no longer applies to any member of the group.
In summary: in this mishnah we examined two of the four categories of vows that do not take effect: nidrei havai, which were stated in the language of exaggeration and which the one who vows never intended to take effect; and nidrei shegagos, which were made based on a mistake in the facts, so that once the mistake comes to light their entire basis falls away. From the case of those eating figs we learned the dispute between Beis Shammai and Beis Hillel, and the principle adopted by Beis Hillel - "a vow that was partially annulled is entirely annulled."