The Gemara answers: Yes, generally they do teach halakhot based upon an a fortiori inference of this type, but here it is different, as the verse states: ''Her husband may ratify it, or her husband may nullify it'' (Numbers 30:14). The Rabbis interpret this to mean: That which has become eligible for ratification, i.e., a vow that she has already taken, has become eligible for nullification. However, that which has not become eligible for ratification, i.e., a vow she has not yet taken, has not become eligible for nullification.

MISHNA: The nullification of vows can be performed all day on the day on which the vow was heard. There is in this matter both a leniency, extending the nullification period, and a stricture, curtailing that period.

How so? If a woman took a vow on Shabbat evening, her father or husband can nullify the vow on Shabbat evening, and on Shabbat day until dark. This is an example of extending the nullification period. However, if she took a vow with nightfall approaching, her father or husband can nullify the vow only until nightfall, since, if it became dark and he had not yet nullified her vow, he cannot nullify it anymore. This is an example of a curtailed nullification period.

GEMARA: It is taught in a baraita: The nullification of vows can be performed all day on the day on which the vow was heard. Rabbi Yosei, son of Rabbi Yehuda, and Rabbi Elazar, son of Rabbi Shimon, said: A vow can be nullified for a twenty-four-hour period from the time it was heard. The Gemara asks: What is the reason for the opinion of the first tanna? The Gemara answers: Since the verse states: ''But if her husband make them null and void on the day that he hears them'' (Numbers 30:13), he derives that the husband can nullify his wife’s vow only until the end of the day on which he hears the vow.

The Gemara asks: And with regard to the Rabbis, Rabbi Yosei, son of Rabbi Yehuda, and Rabbi Eliezer, son of Rabbi Shimon, what is their reason? The Gemara answers: It is written: ''From day to day'' (Numbers 30:15), which indicates that a vow can be nullified from a particular hour on one day until the same hour on the following day.

The Gemara asks: And according to the first tanna, isn’t it written: ''From day to day''? The Gemara answers: That verse is necessary, as if it had said only ''on the day that he hears them,'' I would say that during the day, yes, he can nullify vows, but at night he is not able to. Therefore, it is written: ''From day to day,'' to teach that nullification can be performed even between one day and the next, i.e., night.

The Gemara asks: And according to the one who said that ''from day to day'' indicates a twenty-four-hour period for nullification, isn’t it written: ''On the day that he hears them?'' The Gemara explains here, too: That verse was necessary, as if it had written only ''from day to day,'' I would say that he can nullify a vow for her until the same day in the following week, i.e., he can nullify her vow during the entire period from one Sunday to the next Sunday. Therefore, it is written: ''On the day that he hears them'' to teach that nullification is limited to a period of a single day of twenty-four hours.

Rabbi Shimon ben Pazi said that Rabbi Yehoshua ben Levi said: The halakha is not in accordance with that pair [zug], Rabbi Yosei, son of Rabbi Yehuda, and Rabbi Eliezer, son of Rabbi Shimon, who hold that one has an entire twenty-four-hour period to nullify vows. Rather, one can nullify only on that day, as stated in the mishna. The Gemara relates: Levi thought to act in accordance with the opinion of those two tanna’im. Rav said to him: So said my uncle [ḥavivi], Rabbi Ḥiyya: The halakha is not in accordance with that pair.

The Gemara relates that when a case of dissolving a vow was brought before Ḥiyya bar Rav, he would shoot an arrow [gira] and examine the vow at the same time. In other words, he would not examine the case in great depth, but would immediately dissolve it. Similarly, Rabba bar Rav Huna would sit to review the vow and stand immediately, without conducting a comprehensive examination.