The world was created with ten utterances. The power of speech distinguishes man from animal. Words have a power of their own and can create liabilities that must be honored. “If a man makes a vow (“Neder”) to G-d, or makes an oath (“Shavu’ah”) to obligate himself, he must not break his word. He must do all that he expressed verbally. “But when you have spoken, be careful to keep your word and the pledge that you have vowed to God.” As a result of a Shavu’ah or a Neder, things that the person had no obligation to perform must now be performed and things that would otherwise have been permitted now become prohibited. For example a person might take an oath to run ten miles today or not to eat lunch today. Such an oath is referred to in Halachah as a “Shavu’ath Bitui.
One of the principal distinctions between the Neder, the vow and the Shavu’ah, the oath, is that the Neder creates an obligation with respect to things, “Chovat Cheftza,” whereas the Shavu’ah creates an obligation with respect to the person, “Chovat Gavra.” Accordingly, if a person makes an oath that he will not sit in a Succah, that he will not put on Tefillin, or that he will not eat Matzah on the first night of Pesach, the oath does not exempt him from the duty to perform the obligation, the Mitzvah. This is because we are considered to have already taken an oath at Sinai to perform the Mitzvot. Such an oath is therefore meaningless, a “Shavu’ath Shav and the person uttering it would have violated the Third Commandment against invoking the name of God in vain. A person can, however, make a Neder not to sit in a Succah or not to wear Tefillin by phrasing the prohibition in such a way as to make it apply to the Succah or to the Tefillin rather than to himself. Accordingly if a person utters a vow that “sitting in the Succah is forbidden to me” rather than uttering an oath that “I will not sit in the Succah”, the vow takes effect. Amazingly, such person is now prohibited from sitting in the Succah until or unless the Neder is annulled. The Succah is a forbidden item to him just as if it were a stolen Succah.
The technical explanation for this unexpected result is that whereas breaking a vow violates both the negative commandment of “he must not break his word” and the positive commandment of “he must do all that he expressed verbally,” not sitting in the Succah or not wearing Tefillin violates only a positive commandment and does not violate both a negative commandment and a positive commandment. The philosophical explanation may be that the Torah itself sometimes tells us which Mitzvah is more important in G-d’s eyes. If G-d cannot trust our word, He may not want us in His Succah. Of course this does not mean that we can exempt ourselves from sitting in the Succah by making a Neder. What it does mean is the vow must be annulled before we sit in the Succah. The vow cannot simply be ignored.
There are, however, situations in which even a Shavu’ah can oblige a person to refrain from performing a Mitzvah. Such is the case when a person utters a Shavu’ah that he will not perform an activity, which is a Mitzvah when performed at certain times but is not a Mitzvah if performed at other times For example, rather than swear that he will not eat Matzah on Pesach or sit in the Succcah on Succot which would be meaningless, a person might swear that he will not eat Matzah or sit in the shade for two years. Because this Shavu’ah has application to all those days of the year when it is not a Mitzvah to perform these activities, it applies on Pesach and Succot too. Like the Neder, this type of Shavu’ah will require annulment.
Reprinted with the permission of Raphael Grunfeld, the author of Ner Eyal on Seder Nashim and Nezikin. TO ORDER NER EYAL ON SEDER MOED CLICK HERE ON ShopOU or buy it at your Judaica bookstore. Any questions can be addressed to the author at email@example.com.
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