The
157th prohibition is that we are forbidden from violating any verbal obligation
we have made, even if it was not said as an oath.
These
obligations are known as nedarim
(vows); for example, when a person says, "if a certain event occurs" or "if I
do a certain act" then "all fruit will be forbidden to me" or "the fruit of
this country [will be forbidden to me]" or a certain food, such as milk, fish,
etc. "will be forbidden to me"; or when he says, "deriving pleasure from my
wife is forbidden to me"; or any similar verbal obligation, as explained in
tractate Nedarim. In all these cases he must carry out his vow, and violating
it counts as a prohibition.
The
source of this commandment is G‑d's statement, "He must not yachel ("break") his word. He must do everything that he stated
verbally."
Our
Sages explained the phrase, "He must not yachel
his word" as meaning, "he must not make his word profane (chullin)," i.e., to obligate himself and then not fulfill his
promise. As tractate Shavuos puts it, "vows comes under
the prohibition, 'he must not break (yachel)
his word.' "
The
Sifra says [regarding a case where someone promised
to bring a sacrifice and did not do so], "The verse, 'He must not break'
teaches us that he violates the prohibition of not breaking one's word and that
of not delaying as offering." This means that if a person vowed to bring a
sacrifice, and three holidays have passed by and he still did not do so, then
he is guilty of transgressing the prohibition of not delaying [the offering] and of not breaking his word.
The
same applies to anything resembling a sacrifice, such as promising a gift to
the fund of the Holy
Temple, to charity, to a synagogue, etc.
One
who transgresses this prohibition by doing something he has promised not to, is
punished by lashes.
The
details of this mitzvah are
completely explained in tractate Nedarim.
