01 Apr IS A BEDIKAS CHAMETZ ROBOT KOSHER?

The night before
Pesach, we search
for chametz on our
property (bedikas
chametz). By
rabbinic decree,
it is not enough
to nullify our
chametz but we must also search for,
and destroy, our chametz, as well. The
Roomba, a robotic vacuum cleaner that
autonomously cleans your floors, has
been available for over twenty years.
Imagine a more advanced version, an
autonomous chametz detector (ACD),
with arms and legs that can go through
your whole house (including drawers,
closets, pockets and knapsacks), find any
chametz and remove it. Is a contraption
like that sufficient for bedikas chametz?
I. Machine Checking
Rav Dov Lior (cont., Israel) was asked
a related question. If someone invents
an electronic chametz detector (ECD),
for example a machine the sniffs out
gluten, can the device be used for
bedikas chametz? Rav Lior responds
that if the ECD is tested thoroughly to
ensure it works properly, then a negative

result would be sufficient for bedikas
chametz. However, it is unwise to use
such a machine because of the possibility
of a false positive. What if the ECD is
triggered by a minute amount of chametz
or by chametz that is in a place we are
not required to check? The positive result
would force you to do extra cleaning and
checking (Responsa Devar Chevron,
Orach Chaim, vol. 2 no. 271).
A bedikas chametz machine like that
requires human interaction. Imagine a
machine that autonomously checks for
chametz while you relax or take care of
other things. Can you use that for bedikas
chametz? Effectively, the ACD serves
like an agent, a shali’ach. In general, it is
best for the homeowner to do at least part
of the bedikas chametz by himself rather
than hand off the mitzvah to someone
else (Magen Avraham 432:5). If that is
not possible, he can appoint a shali’ach
to check for chametz. Indeed, it seems
from the Gemara (Pesachim 4b) that in
some places they hired a person to search
for chametz but the homeowner did a
little searching himself (Pri Megadim,
Eshel Avraham 532:5). However, we are
discussing a machine, not a shali’ach.

II. Unrequested Assistance
Consider someone driving
home for bedikas chametz
who gets stuck in traffic.
Ideally, he should call and
appoint someone a shali’ach
to check for him. If he fails to
do so, and a concerned friend,
guest or relative checks
for chametz without being
appointed, does this suffice
for the mitzvah? When the
man finally arrives home
late at night, does he need to
check for chametz? Rav Shlomo Zalman
Auerbach (20th cen., Israel) writes that
bedikas chametz has value even without
being appointed a shali’ach because it
prevents the individual from violating
the prohibition against owning chametz
on Pesach. All Jews are responsible
for each other’s religious wellbeing.
However, a shali’ach fulfills the mitzvah
on behalf of the homeowner and recites
the blessing on bedikas chametz whereas
the unappointed friend does not fulfill
the mitzvah nor recite the blessing
(Minchas Shlomo, second edition, 58:4).
Therefore, when the man finally arrives
home, presumably he must fulfill the
mitzvah and conduct his own search
for chametz even if his friend already
did it.
I believe we see a similar ruling in the
laws of mourning. Someone whose
close relative passes away but has
not yet been buried has the status of
an onen. An onen does not perform
mitzvos, although he is still bound by
the Torah’s prohibitions. What does
an onen do about bedikas chametz?
Rav Yehudah Ayash (18th cen.,
Algeria) writes that while an onen is
exempt from bedikas chametz, others

can check for him on their own (me-
atzmam), meaning without being

appointed a shali’ach. They do not
fulfill the mitzvah and do not recite the
blessing but they help him avoid the
prohibition against owning chametz on
Pesach (Responsa Beis Yehudah, no.
5). Rav Ephraim Zalman Margoliyos
(19th cen., Ukraine) disagrees about the
appointment of a shali’ach. Since this
is a mitzvah with a limited timeframe
that can be fulfilled with no effort,
an onen can appoint a shali’ach to
do bedikas chametz who then recites
the blessing (Hilchos Onen, par. 8).
According to Rav Ayash, someone
who is not appointed a shali’ach can
do bedikas chametz for another person.
Rav Margoliyos does not disagree but
believes we do not need that concept

for an onen. More recently, Rav Nassan
Gestetner (20th cen., Israel) questions
Rav Margoliyos’ claim that an onen,
who is exempt from the mitzvah, can
appoint a shali’ach. If he is exempt, then
he cannot appoint someone else to do a

mitzvah from which he is exempt (Le-
Horos Nassan, vol. 13 no. 93).

III. Man and Machine
We see that someone or something
that is not a shali’ach cannot fulfill the
mitzvah for a person. A machine cannot
be a shali’ach and therefore cannot fulfill
the mitzvah of bedikas chametz for its
owner. One could suggest that a machine
is merely an extension of its owner. For
example, someone who uses a feather
and spoon during bedikas chametz to
gather pieces of chametz is using the
feather and spoon as an extension of his
hands. No one would suggest that he
does not fulfill the mitzvah because he
is using utensils. However, he holds the
utensils in his hands so they are literally
extensions of him. In contrast, the ACD
moves autonomously, independent of
any person, and cannot be considered an
extension of the person.
Rav Lior (loc. cit.) adds another
possibility regarding the electronic
chametz detector. Rav Shlomo Kluger
(19th cen., Ukraine) writes that a room
obtains a different status if it is cleaned
completely of chametz more than three
days before the night of bedikas chametz.
After three days without chametz, the
room gains a presumption (chazakah) of
lacking chametz. It is like a room where
chametz is never brought that does not
require bedikas chametz (Chochmas
Shlomo 433:11). If you use a chametz
detector three days before bedikas
chametz, any room it declares free of
chametz does not need to be checked
(assuming no one brought new chametz
there). Similarly, you can use an ACD to
clean your house of chametz three days
before bedikas chametz. Although you
should still check one room just to fulfill
the mitzvah.