On today’s daf, we encounter a mishnah that asks what happens when a person swears not to do a mitzvah. Are they in fact bound by that statement?
Regarding one who said, “Making a sukkah is konam for me,” “Taking a lulav is konam for me,” or “Laying tefillin is konam for me,” in the case of vows, they are forbidden, but in the case of oaths, they are permitted, as one cannot take an oath to transgress the mitzvot.
In our mishnah, a person states that making a sukkah, taking up a lulav or wrapping tefillin are all konam — a substitute word for korban, referring to a Temple sacrifice. By making such a statement, the person is using a formula that is intended to have the same weight as one who would have sought to render those three objects set aside for Temple use and thus forbidden to them. According to the mishnah, if the formula a person uses when forswearing one of these objects is a vow, the object is in fact forbidden to them. But if the person swears an oath, the oath has no effect, since one cannot swear an oath not to do a mitzvah. (Don’t worry, we’ll get to the difference between these terms soon.)
The Gemara tries to back up this ruling with a prooftext:
Rav Giddel said that Shmuel said: From where (is it derived) that one cannot take an oath to transgress the mitzvot? The verse states: “He shall not profane his word” (Numbers 30:3). His word he shall not profane. However, he may profane it for the desires of Heaven.
In seeking the source for the mishnah’s rule, Shmuel cites a verse in Numbers stating that one who makes a vow shall not fail to abide by that vow. Shmuel concludes that someone must not profane their words by failing to do that which they say they are going to do — except in cases in which they swear to do something contrary to God’s desires.
A complication with this explanation is that Numbers 30:3, from which our daf only quotes a portion, explicitly refers to both a vow and an oath, making no distinction between the two. How does the mishnah then rule that a vow can override a mitzvah but an oath cannot?
Enter Abaye, who argues that the ruling in the mishnah derives from the different ways the person makes their statement.
Abaye said: This case (in which the prohibition overrides the mitzvah) is referring to one who said: The benefit derived from a sukkah is hereby forbidden to me. That case (in which the prohibition does not take effect) is referring to one who said: I hereby take an oath that I will not derive benefit from the sukkah.
To understand Abaye’s argument, we need to recall the difference between vows and oaths. A vow places a prohibition on an object, while an oath places a prohibition on the person swearing the oath. In the case of a vow, the person is placing the prohibition on the sukkah itself, stating that any benefit from the sukkah is forbidden to him. In the case of an oath, the person is placing the prohibition on himself, stating that he cannot derive any benefit from a sukkah. The latter case would not be binding, as one cannot take an oath not to do something that is obligatory. But one can state that a particular object is forbidden.
Rava disagrees with this interpretation.
Rava said: But were mitzvot given for deriving benefit? Rather, Rava said: This case (is referring to) one who said: “Dwelling in a sukkah (is hereby prohibited) to me,” and that (case is referring to one) who said: “I hereby take an oath that I will not dwell in a sukkah.”
Rava takes issue with Abaye’s claim that one is deriving benefit from the performance of a mitzvah, and thus brings us back to the essence of the matter: Did the person disavow using the item, or swear not to do the mitzvah? In the first case, the vow sticks. In the second case, the oath does not.
Finally, what do we make of this disagreement between Abaye and Rava about whether the mitzvot are there for our benefit? The 19th-century commentator Rabbi Yehuda Aryeh Leib, known as the Sfat Emet, weighs in on this with a beautiful reflection in his commentary to the Torah portion Yitro, in which the giving of the Ten Commandments is described:
“But people that understand know that this [receiving the Torah] is not a small thing and that they are receiving with this a great and awesome yoke to serve the Creator of the world and to clarify his kingdom, may it be blessed, in the world … And in the Gemara we also find a disagreement whether commandments were given to us to derive benefit from. And the law is that they were not given to us to derive benefit from.”
The benefit, according to the Sfat Emet, is not deriving pleasure from the mitzvot, but rather the satisfaction of serving God. That is why a person can make a vow not to use a certain object, but they cannot swear not to do the mitzvah at all.
Read all of Nedarim 16 on Sefaria.