In the beginning of this week’s parshah, the Torah teaches the halachos of nedarim.
There are two types of nedarim. One type is when one vows to bring a korban. This vow is binding; thus, one must keep his word. The other type of neder is when one forbids something either on himself or on others that would otherwise be permitted. One can only prohibit others from using something that belongs to him, while he may prohibit himself even from something that does not belong to him. This is the type that the Torah discusses in this parshah. Yet the laws that the Torah discusses here bind both types of nedarim, namely that one must keep his word.
There are several rules that one must adhere to when making a neder. He must recite the neder – not think of doing it. He must also say that the item that he wishes to prohibit should become forbidden, the same way as something else is forbidden. For example, he can say that an apple is forbidden, just as a korban is forbidden.
There are specific prohibitions to which one must liken his neder. The general rule is that it must be a prohibition that man is involved in making, such as a korban requiring human intervention in order to become a korban. One may not say that an apple should become as forbidden as a pig since pigs are prohibited without human involvement.
I will now digress to the end of the parshah, and connect it to the beginning. At the end of this week’s parshah, we learn of the arrangement between the bnei Gad and Reuven to remain on the other side of the Yarden. Moshe Rabbeinu ultimately makes this arrangement contingent on their fighting in the wars in Eretz Yisrael. We learn from this episode the halachos of making conditions.
One halacha that we learn about making conditions is that if the condition is to be valid, one must repeat the condition in the negative. For example, one must say that this is contingent on such and such, and if such and such does not happen the transaction is invalid.
The Gemara in Kesubos 74a says that another halacha that we learn from the condition of bnei Gad and Reuven is that in order to make something contingent on something else the transaction must be able to be accomplished by a shaliach. If the transaction is unable to be performed by a shaliach, one may not make it contingent on any clauses. We learn this from the fact that Moshe made Yehoshua his shaliach to distribute the land. Tosafos there explains that although we do not require that every aspect of a contingency situation be similar to the case of bnei Gad and Reuven, we do conclude that the transaction must be accomplishable via a shaliach because that determines how much control one has over the transaction. A transaction that one can close by means of a shaliach is more in his control, and it is in such cases that the Torah allows him to make it contingent on other factors. A transaction that can only be executed by the person is not in his control as much, and he may not make it contingent on anything.
Returning to the beginning of the parshah, Tosafos in Nazir 11a asks how one can make a neder to become a nazir contingent on another factor; after all, becoming a nazir is not something that he can do through a shaliach. (Tosafos specifically asks about becoming a nazir, but the same applies to all nedarim.) Tosafos answers that since one can appoint a shaliach to bring his korbanos, it is considered as if the entire process is accomplishable by a shaliach – and therefore can be made contingent on something.
Tosafos’s answer does not answer the question of how one can make a neder contingent on other factors. Rav Chaim Soloveitchik, zt”l, suggests a different answer that would explain making a neder both to become a nazir and prohibiting something contingent on other factors. He explains that, in essence, one can appoint a shaliach to make him a nazir or to make a neder to prohibit him from something – just as he can appoint a shaliach to buy or sell something on his behalf. The reason why one cannot actually appoint a shaliach to do this is because of something else, not because the neder is not enough in his control to appoint a shaliach. The reason why one cannot appoint a shaliach is because there is a halacha that words cannot be given to a shaliach. If the only thing that a shaliach must execute is verbal, the shelichus is invalid. A shaliach must also be responsible to execute actions. Since nedarim only require verbal enunciations, they cannot be made via a shaliach.
Rav Chaim says that Tosafos’s explanation that the reason for the requirement that a transaction be capable of being performed by a shaliach in order for its allowance to be contingent on something else is because the transaction is otherwise not considered to be enough under his control. Since, in essence, nedarim would be able to be executed by a shaliach, they are considered enough under one’s control to make them contingent on other factors.