THOUGHTS ON THE DAILY DAF
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Rosh Kollel: Rav Mordecai Kornfeld
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1) "HANG THE DOOR POSTS FIRST"
OPINIONS: The Gemara relates that when the Reish Galusa built a house and
requested from Rav Nachman that he affix the Mezuzah, Rav Nachman said that
the "Dashei" should be hung first. What is the "Dashei," and why was it
necessary to erect it before affixing the Mezuzah?
(a) RASHI explains that "Dashei" refers to the door frames. They must
precede the Mezuzah, because if the Mezuzah is affixed to the entranceway
first, and then the door posts are erected, the Mezuzah will be invalid
because of the rule, "'Ta'aseh v'Lo Min ha'Asuy." The Mezuzah must be
affixed to the entranceway of a house that is already built. If the Mezuzah
is affixed before the house is completed, it is not valid.
(b) While TOSFOS does not argue with Rashi's application of the Halachah of
"Ta'aseh v'Lo Min ha'Asuy" to the laws of Mezuzah, he claims that this
explanation is not consistent with the wording of the Gemara. According to
Rashi's explanation, Rav Nachman should have told the Reish Galusa to hang
the "Sifei" (door posts) first, and not the "Deshe," which means "door." (It
could be that Rashi understood the word to mean door posts, because in his
Girsa, as well as in the Girsa of our texts, the word is "Dashei," in the
Tosfos explains instead that it was necessary to attach the door in order to
know which direction the door would open (the "Heiker Tzir"). Tosfos
understands that this story is a continuation of the previous Gemara which
discusses a case in which it was not clear which direction was the "Derech
Bi'ascha," the way from which one entered the doorway. Rav Nachman told the
Reish Galusa that it was necessary to first attach the door in order to
discern the side towards which the door opens, so that the Mezuzah can be
placed on the right of the side which is "Derech Bi'ascha."
We may ask, however, that according to the explanation of Tosfos, why was it
necessary for Rav Nachman to tell the Reish Galusa to attach the door? If
Rav Nachman merely needed to ascertain which direction was "Derech
Bi'ascha," he should have simply asked the Reish Galusa on which side he
*planned* to attach the door! With that information, Rav Nachman would have
known on which side to affix the Mezuzah!
RAV MOSHE FEINSTEIN zt'l (Igros Moshe YD 1:176) derives another practical
Halachah from the fact that Rav Nachman did not merely ask the Reish Galusa
on which side he planned to attach the door. Rav Moshe rules that a doorway
that has no "Heiker Tzir" -- that is, either there is no door in the doorway
(according to the Rishonim who maintain that a doorway does not need a door
in order to be obligated to have a Mezuzah), or there is a door that opens
in both directions (such as a swinging door) -- does not require a Mezuzah!
Since the "Derech Bi'ascha" cannot be established, there is no obligation of
Mezuzah at all. This is why Rav Nachman required that the Reish Galusa
attach the door and thereby establish the "Derech Bi'ascha" before he
affixed the Mezuzah; without knowing for certain which way was "Derech
Bi'ascha," there was no obligation to affix a Mezuzah there. The intention
in the mind of the Reish Galusa cannot establish the direction of the
passageway, the "Derech Bi'ascha."
Rav Moshe adds that this exemption applies only when we actually need the
"Heiker Tzir" in order to determine the direction of "Derech Bi'ascha." If
the "Derech Bi'ascha" is obvious from the general direction of the public
traffic through the entranceway, then the obligation to affix a Mezuzah
takes effect without the need for a "Heiker Tzir."
Not all of the Poskim agree with Rav Moshe's ruling that a doorway without a
"Heiker Tzir" (when one is necessary) is not obligated to have a Mezuzah.
Rav Moshe himself quotes the SHE'ELAS YA'AVETZ who maintains that in the
case of such a doorway, a Mezuzah should be affixed to *each side* of the
doorway out of doubt. Others (see MIKDASH ME'AT) maintain that since there
is no clearly discernable "Derech Bi'ascha," the Mezuzah may be affixed on
either side of the doorway. (See a summary of the opinions cited by SEFER
CHOVAS HA'DAR 8:5.)
(c) The RAMBAM, too, agrees that it is sometimes necessary to have the
"Heiker Tzir" in order to ascertain on which side of the door post the
Mezuzah should be placed, but he claims that this explanation is also not
consistent with the wording of the Gemara. The Rambam, in a Teshuvah to the
Chochmei Lunil (cited by the KESEF MISHNEH, Hilchos Mezuzah 6:5), argues
with Tosfos' assertion that this story is a continuation of the previous
Gemara. (In a witty remark, the Rambam says, "Ein Dorshin Semuchin" -- we do
not expound the meaning of one Sugya based on an inference from an adjacent
The Rambam explains that the Gemara is discussing the main entranceway into
the house, where there is no doubt about the direction of "Derech Bi'ascha."
Why, then, did Rav Nachman tell the Reish Galusa to erect the door first?
The Rambam learns that the obligation to affix a Mezuzah applies only to an
entrance way that actually has a door. He derives this from the verse, "Al
Mezuzos Beisecha u'vi'She'arecha" (Devarim 6:9). The Rambam understands
"u'vi'She'arecha" ("and upon your gates") to refer to the gates of our
houses and the gates of our courtyards, and that a gate always has a door.
Therefore, the obligation to affix a Mezuzah applies only to an entranceway
that has a door.
The Rambam continues to explain the Gemara here. Did the Reish Galusa, who
asked Rav Nachman to affix the Mezuzah before the door was attached,
maintain that an entranceway is obligated to have a Mezuzah even without a
door? From the fact that Rav Nachman responded, "hang the door *first*," and
not merely, "Hang the door," it seems that the Reish Galusa agreed that only
an entranceway that has a door is obligated to have a Mezuzah, and he merely
held that the door may be attached *after* the Mezuzah is affixed. Rav
Nachman told him that the door must be attached first, because otherwise
there is a problem of "Ta'aseh v'Lo Min ha'Asuy," as Rashi explains.
(Mordechai Zvi Dicker)
2) A MEZUZAH ON AN "ACHSADRAH"
QUESTION: Rav Chisda states that an Achsadrah (a structure covered by a roof
and enclosed on three of its sides) is exempt from the obligation to have a
Mezuzah, because it has no door posts ("Petzimin"). This exemption is based
on the verse that says that a Mezuzah must be placed "Al Mezuzos Beisecha,"
"on the door posts of your houses" (Devarim 6:9), which implies that a
doorway that has no door posts is exempt.
Rav Chisda's statement implies that if an Achsadrah *does* have door posts,
then it is obligated to have a Mezuzah. The Gemara questions this, saying
that when door posts are erected at the entranceway of an Achsadrah, they
are merely for the purpose of holding up the ceiling and not for the purpose
of enclosing the Achsadrah. Therefore, they cannot be considered "Mezuzos
Beisecha" to be obligated to have a Mezuzah!
The Gemara answers that this indeed was Rav Chisda's intention. When Rav
Chisda said that an Achsadrah is exempt from a Mezuzah, he meant that it is
exempt even if it has door posts, since the door posts are merely for the
purpose of holding up the ceiling.
The Gemara continues and questions Rav Chisda's statement from a Beraisa
that says that an Achsadrah is obligated to have a Mezuzah. The Gemara
answers that the Beraisa is referring to a different type of Achsadrah, a
"Roman Achsadrah" (see Rashi).
Why does the Gemara ask only on Rav Chisda's ruling from the Beraisa's
statement? The Gemara should question the Beraisa's statement by itself,
even without Rav Chisda's ruling! We see from the first stage of the Gemara
that the Gemara assumes that an Achsadrah is exempt from a Mezuzah even when
it has door posts, since those posts are only for supporting the ceiling.
The Gemara, therefore, should challenge the Beraisa -- which says that an
Achsadrah is obligated to have a Mezuzah -- even without Rav Chisda's
ruling! Why is the Beraisa's statement problematic only according to Rav
Chisda? (CHAZON ISH)
ANSWER: RAV CHAIM KANIEVSKY shlit'a (in MASECHES MEZUZAH #19) answers this
question based on the opinion of the ROSH. The Rosh (#14) writes that the
"heads of walls" can be obligated to have a Mezuzah, since they are
considered like door posts. That is, if a house has three walls and the
fourth direction is entirely open, one must affix a Mezuzah at the side of
the opening. This is because the heads of the walls (which one faces as he
enters the open house) on each side of the opening are considered to be
"door posts" ("Petzimin"). (The Acharonim explain that when the walls on
each side of the entrance way also serve as walls for additional rooms on
each side, the Rosh agrees that additional door posts must be built at the
entranceway between the two walls in order to affix a Mezuzah.)
The PERISHAH asks that if, as the Rosh says, the "heads of walls" can
obligate an entranceway to have a Mezuzah, then why is an Achsadrah exempt?
Even though the posts serve to support the ceiling, the heads of the walls
should obligate the Achsadrah's opening to have a Mezuzah!
Rav Chaim Kanievsky answers that there is a basic difference between a house
and an Achsadrah. The walls of a house are built for the purpose of
enclosing the house from all directions. The Rosh maintains that when the
two facing, parallel walls end on one side with no fourth wall attached to
them, we view the thickness of the head of each wall as though it is meant
to demarcate and close off the fourth direction.
An Achsadrah, in contrast, is generally built with only three walls, with no
intention to entirely enclose the area inside. The fourth side is left open
for air, light, and so on. Therefore, the two facing walls on the two sides
of the opening are meant only to serve their own respective sides, and not
to demarcate and close off the fourth side. This is Rav Chisda's logic when
he exempts an Achsadrah from a Mezuzah, even though a similarly-constructed
*house* would require a Mezuzah (according to the Rosh). The underlying
principle of his ruling is that a wall that is not meant to close off an
open side of a structure is not considered a "door post" for that open side.
This is also the intention of the Gemara when it asks that according to Rav
Chisda, an Achsadrah with door posts should not be obligated to have a
Mezuzah, since the posts serve only to support the ceiling. The Gemara is
asking according to Rav Chisda's own logic, that posts that are not meant to
demarcate and close off an open side do not obligate the opening to have a
This also explains why the Gemara has a difficulty with the Beraisa only
according to the ruling of Rav Chisda. Without Rav Chisda's ruling, the
Beraisa that says that an Achsadrah needs a Mezuzah is easy to understand.
The Beraisa is referring to an Achsadrah with posts, and it does not require
that the purpose of the posts be to close off the open side. Only according
to Rav Chisda's logic -- that a wall or a post that is not meant to close
off an open side of a structure is not considered a "door post" for that
open side -- is the Beraisa's ruling problematic. (Mordechai Zvi Dicker)