Fasting in Nisan
On the first day of the month of Nisan, the Mishkan
was erected by the Jews in the desert, and on each of the
twelve ensuing days, the leaders of the twelve tribes brought
offerings to Hashem.
This historic event, combined with the annual festival of
Pesach, transforms the whole of Nisan into a joyous time.
Fasting is prohibited throughout the entire month.
On erev Pesach, we have an exception to this rule, and
every firstborn male fasts Ta'anis Bechoros —
the Fast of the Firstborn (Maseches Sofrim 20, 3).
(This year because erev Pesach is on Shabbos, the Fast
is on Thursday, 12 Nisan.)
In general, national fasts are either a sign of mourning over
the destruction of the Temple, or to facilitate repentance.
Ta'anis Bechoros was established to commemorate the
miraculous salvation of the Jewish firstborns when Hashem
passed through Egypt killing all firstborn (Tur
On Chanukah and Purim the Jewish people faced complete
annihilation — Chanukah on a spiritual and Purim on a
physical level. In both instances, joyous festivals were
instituted to remember the miracles that Hashem performed for
us. If so, why did our Sages treat the miracle of the Plague
of the Firstborns differently and mark it with fasting rather
than with rejoicing?
On the night of the 15th of Nisan as the Jewish people were
celebrating their first Seder and preparing to leave Egypt,
the threat of death loomed over all firstborn in Egypt. Every
Jewish household was commanded to take an "agudas
ezov" (a bundle of hyssop) and to use it to wipe lamb's
blood on the doorposts of their homes from the Korbon
Pesach. This would distinguish the Jewish from the
Egyptian homes as the miraculous plague passed through.
Even though Hashem had promised that the Jewish people would
be spared from this punishment, the firstborn Jewish males
felt some degree of trepidation on the night of the plague.
In order to guarantee their protection, all of the Jewish
firstborns fasted on the 14th of Nisan. Their actions
established a precedent, and as a result our Sages
established a fast on that day (Chasam Sofer, Pesochim
The Sage Rav Sheishes would fast the entire erev
Pesach. We do not base the general halacha on Rav
Sheishes' actions for he was an istenis (someone who
is easily satisfied by food). If Rav Sheishes would even
taste something in the morning he would not be able to
perform the mitzvah of eating matzoh with an appetite at
night (Pesochim 108a). Most of us are not like that.
However, a firstborn who will not have an appetite at night,
if he eats in the day, should fast on erev Pesach.
As long as erev Pesach is on a weekday, any
istenis (even not a firstborn) can deal with his weak
appetite by joining the firstborns in their fast. However,
when Pesach starts on Saturday night (like this year), he is
obligated to eat Shabbos meals beforehand. What is the
correct course of action in such a situation?
Regarding such situations our Sages say, "a wise person has
eyes in his head." A person with such a constitution should
eat the minimum amount required to fulfill the mitzvah of the
Shabbos meals (slightly more than a kebeitzoh). This
should leave him with enough appetite for the matzoh later on
(Mishna Berurah 470,1).
Making a Siyum
Some authorities suggest that if a firstborn is invited to a
bris milah on the 14th of Nisan he can participate in
the festive meal and is not obligated to make up the fast at
a later date (Mogen Avrohom 470). Others extend this
to any seudas mitzva (Pri Chodosh). Based on this
ruling, on erev Pesach most firstborns attend a
siyum of a maseches and consider that this
frees them from their obligation to fast. Even though they
personally did not study the material, since they are joining
the celebration of a person who did, they are permitted to
eat (Mishna Berurah 470,10).
Must one finish a tractate of Talmud in order to make
HaRav Moshe Feinstein said that there is a mitzvah to make a
siyum upon completing any section of Torah which was
studied over an extended period of time. Therefore even if
one finishes just one of the twenty-four books of Bible, a
celebration may be held.
Rav Moshe adds that in order to make a siyum on a book
of the Bible, one must learn it with one of the accepted
commentaries of the Rishonim, and not with a lesser
commentary. Similarly, one should try not to learn the
material quickly just as an excuse to make a siyum.
The underlying principle is that one should only make a
celebration if the book took long enough to learn that one
naturally feels joy upon its completion (Igros Moshe
Fasting or Eating
The Oruch HaShulchan notes that the practice to join a
siyum has become so widespread that almost no
firstborns fast nowadays. If, however, our Sages established
erev Pesach to be a day of fasting for firstborns, do
we really have the power to eliminate this entirely? He
suggests that the tremendous amount of work we do on erev
Pesach combined with the consumption of morror on
Seder night makes it very difficult to fast on erev
Pesach. Since this fast is only a custom and is not
mentioned in the Talmud, the rabbis did not see fit to
protest its virtual non-observance (Oruch HaShulchan
Another point is that fasting has an effect on the stomach,
making it constrict. So fasting makes it difficult to perform
the mitzvos of eating on Seder night afterwards
(Olas Shmuel 28). Thus, it is the general custom to be
lenient and to avoid the fast by making or attending a
siyum. However if a firstborn knows that he has the
strength and stamina to fast on erev Pesach and still
participate fully in the Seder, it is praiseworthy to
follow the time-honored custom of fasting (Igros Moshe
The Mishna Berurah adds that if one feels very sick as
a result of not eating, he may break the fast even if he
didn't attend a siyum. So too if he knows that fasting
will hinder his ability to eat matzoh and morror and
to drink the four cups of wine, he is not obligated to fast.
Nonetheless, he should avoid eating bread (which is only
permitted until about 9 a.m.), as explained in the following
section (Mishna Berurah 470,2).
There is a fundamental dispute amongst the Rishonim as
to the nature of Ta'anis Bechoros. Most agree that it
is a regular fast day. Therefore if one did not attend a
siyum and has no other exemption, e.g. feeling sick,
he is not allowed to eat anything during the day.
But some Rishonim maintain that this fast differs from
all other fasts, and one is only forbidden to eat filling
foods such as bread or other wheat products. According to
this view, foods such as fruits and vegetables may be
consumed (Rabbeinu Yechiel as cited in the Mordechai).
What is the meaning of a fast on which it is permissible to
All Jews must refrain from eating these types of foods in the
afternoon of erev Pesach so that we have an appetite
for the matzoh (Shulchan Oruch 471,1). As a further
precaution (that the mitzva should be performed with the
proper enthusiasm), firstborns are instructed to watch what
they eat for the entire day.
Ultimately, we follow the first opinion and firstborns are
not allowed to eat on Ta'anis Bechoros at all.
However, as mentioned previously, if one did not attend a
siyum and knows that the mitzvos of erev Pesach
and Pesach will tire him out (to the point that he will not
fulfill his obligations properly), he may eat. However, since
some Rishonim reason that one is only forbidden to eat
wheat products and other satisfying foods on this day, it is
preferable to eat only fruit, vegetables and other lighter
foods (Mishna Berurah 470,2).
Who is a Firstborn?
Our Sages tell us that during the Plague of the Firstborn at
least one person died in every Egyptian household, and in
some homes there were a number of deaths. As is well known
from the halachos of pidyon haben, there are
many factors that can exclude a child from being considered a
bechor. Therefore, it is very unlikely that there was
a bechor in every household. But surely it is
impossible that there was more than one firstborn in one
The Midrash states that as a result of the prevalent
immorality in Egypt, some parents had firstborn children from
more than one partner. Since all of these children shared
firstborn status, they all died during the plague. Based on
this, the custom is for every firstborn child to fast, be he
the firstborn of his father or of his mother (Shulchan
In a house where there was no bechor in Mitzrayim, the
eldest child of the family died. Nonetheless, nowadays an
oldest child who is not a firstborn does not fast. Even if
there is no other bechor in the household he may eat
without attending a siyum (Tur as cited by
Mishna Berurah 470,2).
The Midrash relates that the firstborn Egyptian girls
also died during the Plague of the Firstborn. Based on this,
the Shulchan Oruch cites an opinion that firstborn
women are also obligated in Ta'anis Bechoros. Does
this mean that women must attend a siyum in order to
Since many opinions hold that they are not obligated to fast,
some Sephardic authorities write that a women may eat on
erev Pesach as long as she ate food from a
siyum, even if she did not attend the actual
celebration (Yechaveh Daas 4,42). The Ramo rules that
women are not included in this fast, since they do not have
the bechor status regarding other matters (470,4).
A birth via a Caesarean section presents a fascinating
halachic issue, and the poskim discuss whether a child
born this way is obligated to fast on Ta'anis
Bechoros. Such a child is not considered a firstborn with
regard to receiving a double portion of inheritance, but
there are some who argue that because he is the firstborn
child of his mother he should fast (Chok Yaakov
470,2). Others write that since his status is uncertain, he
need not fast (Kaf HaChaim 470,3).
Our Sages chose to commemorate dates when terrible tragedies
befell the Jewish people with fast days. On a personal level,
the Ramo recommends fasting on the yahrtzeit of one's
parents. On a national level, we are instructed to fast on
the 17th of Tammuz, the 10th of Teves, the 3rd of Tishrei and
the 9th of Av — all dates when devastating calamities
Perhaps this is a further reason why firstborns are
instructed to fast on erev Pesach. After the Plague of
the Firstborn took place on the 15th of Nisan, this date
became a time of historic foreboding for firstborn children.
The merit of Ta'anis Bechoros on erev Pesach
continues to protect them from all harm.