Talmud - Nedarim 18a נדרים י״ח א׳

and this is a conclusive refutation of the statement of Rav Huna.

The Gemara answers: No, actually the case is where he said: I am hereby a nazirite today, I am hereby a nazirite tomorrow. And what is the meaning of the statement: The second term of naziriteship is counted for him instead of the first? It is counted except for that additional day, which he still must observe. Alternatively, it may be a case where he accepted upon himself two periods of naziriteship simultaneously, i.e., he said: I am hereby a nazirite twice. Therefore, when the vow with regard to the first term of naziriteship is dissolved, the days he observed count entirely for his second term.

Rav Hamnuna raised an additional objection against the opinion of Rav Huna from a baraita. It is stated in the verse: “A nazirite, to consecrate [nazir lehazzir]” (Numbers 6:2). From the use of similar, repetitive wording in the verse here it is derived that naziriteship takes effect upon a prior vow of naziriteship. As one might have thought that it could be derived through an a fortiori inference that naziriteship does not take effect, as follows: And just as with regard to an oath, which is more stringent, an oath does not take effect upon a prior oath, with regard to naziriteship, which is more lenient, all the more so is it not clear that it does not take effect where a vow of naziriteship was already in effect? Therefore, the verse states: “Nazir lehazzir.” From here it is derived that naziriteship takes effect upon a prior vow of naziriteship.

What are the circumstances? If we say it is a case where one said: I am hereby a nazirite today, I am hereby a nazirite tomorrow, does that case require proof from a verse that it takes effect? It is obvious that the second vow of naziriteship takes effect at least on the additional day. And as the minimum term of naziriteship is thirty days, an additional thirty days must be observed. Rather, is it not a case where one said: I am a nazirite today, I am a nazirite today? And the baraita teaches that in this case as well, naziriteship takes effect upon a prior vow of naziriteship, contrary to the opinion of Rav Huna.

The Gemara answers: That is not the case. Rather, with what are we dealing here? We are dealing with a case where he accepted upon himself two terms of naziriteship simultaneously. The baraita teaches that he must observe two terms of naziriteship and bring a separate offering for each.

The baraita stated that an oath is more stringent than a vow. The Gemara asks: And what is the stringency of an oath vis-à-vis a vow, such as a vow of naziriteship? If we say the baraita posits this because an oath, unlike a vow, takes effect even with regard to a matter that has no actual substance, there is a counterargument that a vow also has stringency vis-à-vis an oath, in that it, unlike an oath, takes effect with regard to a mitzva just as it does with regard to a matter that is permitted. Rather, oaths are more stringent because it is written with regard to an oath: “The Lord will not hold guiltless he who takes His name in vain” (Exodus 20:6).

§ It is taught in the mishna that if one said: I hereby take an oath that I will not eat, I hereby take an oath that I will not eat, and he then ate, he is liable to bring an offering for only one violation of an oath. Rava said: If he requested and received dissolution from a halakhic authority for the first oath, the second oath takes effect upon him. From where is this derived? From the fact that it is not taught in the mishna that there is only one, i.e., it is as though he took only one oath as the oaths are identical. Rather, it is taught that he is liable for only one. Evidently, he is not liable for the second oath only because it does not have a span of time in which to take effect, as he is already under oath not to eat. However, when he requests dissolution of the other oath, i.e. the first oath, the second oath has a span of time in which to take effect, and takes effect.

Another version of Rava’s proof from the mishna is that it may be inferred from the statement: He is liable for only one, that although there is no liability to bring an offering for violating the second oath, there is an effective oath. But if there is no liability, then with regard to what halakha is it effective? Certainly it is effective with regard to the statement of Rava, as Rava said: If he requested and received dissolution from a halakhic authority for the first oath, the second is counted for him in its place.

The Gemara proposes: Let us say that the following mishna (Shevuot 27b) supports his opinion: In the case of one who took two vows of naziriteship, and counted the first term, and set aside an offering, and requested and received dissolution from a halakhic authority for the first oath, the second term counts for him instead of the first. Evidently, although initially the second term of naziriteship did not have a span of time in which to take effect, it was not completely void. Therefore, when the first vow was dissolved, the second one immediately took its place. It may be proved from here that this is true with regard to oaths as well.

The Gemara refutes this proof: That mishna may be referring to a case where he accepted upon himself two terms of naziriteship simultaneously. Since two terms cannot be observed concurrently, when he accepts two terms simultaneously, the halakha is that the second term commences immediately following the close of the first, which immediately took effect upon sequential periods of time. However, when one takes an oath prohibiting himself from a matter that is already prohibited by an oath in the same period of time, the second oath may not take effect at all.

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Nedarim 18a examines whether a second nazirite vow takes effect over an existing one, exploring overlapping vows and comparisons to oaths.