Shulchan Aruch: Chapter 485 - The Laws Pertaining to a Person who Took an Oath Not to Eat Matzah

SECTION 485 The Laws Pertaining to a Person who Took an Oath Not to Eat Matzah (1-3)

1 A person who took an oath not to eat matzah on the night of Pesachshould be compelled to eat [it.1 The rationale is that] an oath to nullify any Scriptural commandment never takes effect, for [the person] is already bound by oath to [fulfill the commandments] from [the Giving of the Torah at] Mount Sinai [onward].2

[In the era when there where judges with the semichah dating back to Moshe, our teacher,]3 whether [such a person] ate matzah on Pesach night or refrained from eating, he would be given lashes4 because he took an oath to nullify [the observance of] a mitzvah. [The rationale is that] since it is impossible for him to nullify [the observance of the mitzvah]since he is bound by [the] oath [taken at Sinai] to fulfill it, he is considered as one who took an oath to perform an act that cannot be performed. [A person who takes such an oath] is given lashes for taking a false oath,5 as explained in Yoreh Deah, sec. 236.6

2 When does the above apply? When [the person] specifically mentioned the night of Pesach [in his oath. The above ruling applies] whether he took the oath on [Pesach] night or beforehand.

[However,] if [a person] takes an oath not to eat matzah without mentioning the night of Pesach, since the oath takes effect with regard to [eating] matzah [when it] is left to his discretion, i.e., before [Pesach] night and afterwards,7 it also takes effect with regard to [eating] matzah on Pesach night.⁴ [The rationale is that such] an oath is effective [even though it involves] the nullification of [the observance of] a mitzvah, [when doing so does not involve activity, but rather simply] remaining passive, [provided the oath] also includes [refraining from] a matter left to a person’s discretion.

All the above applies to an oath. (With regard to which wording connotes an oath according to Scriptural Law or according to Rabbinic Law, see Yoreh Deah, sec. 237.)8

By contrast, if one takes a vow not to eat matzah on Pesach night, for example, he says, “Eating matzah [for the sake of fulfilling the] mitzah is forbidden to me as a vow,” he is forbidden to eat [matzah],² for vows take effect [even] with regard to matters associated with a mitzvah, as explained in Yoreh Deah, sec. 215.9 Nevertheless, [the person] should be compelled to release his vow by making a request [of a sage] and expressing regret,10 as explained in Yoreh Deah, loc. cit.11

3 When one takes an oath not to drink [the] four cups [of wine mandated by our Sages] on Pesach night, or not to eat maror [that night] in the present age when [eating maror is] a Rabbinic ordinance,12 or not to eat matzah on the second night [of the festival observed in the Diaspora],13 the oath takes effect. [The rationale is that] an oath to nullify a Rabbinic commandtakes effect when one remains passive. Nevertheless, it is appropriate to compel [the person] to release his oath by making a request [of a sage] and expressing regret, and [then] fulfill the mitzvah. [Such a course of action is appropriate] even if [as in the case above,] he included in his oath matters left to his volition.