THOUGHTS ON THE DAILY DAF
brought to you by Kollel Iyun Hadaf of Har Nof
Rosh Kollel: Rav Mordecai Kornfeld
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1) SWIMMING IN A PRIVATE POOL OR BATH ON SHABBOS
OPINIONS: The Gemara says that it is forbidden to be "Oker" (Rashi: lift up
one's feet) in a pool, even if the pool is in a Reshus ha'Yachid, if the
pool does not have "Gedudi" (a rim around it). Why is this prohibited?
(a) RASHI explains that "Oker" refers to lifting one's feet off of the
floor of the pool, which is prohibited because it constitutes swimming --
an activity that the Rabanan forbade on Shabbos. Thus, if the pool does not
have "Gedudi," one may go into the pool on condition that he not lift his
feet from the floor.
HALACHAH: The SHULCHAN ARUCH (OC 339:2) rules like the Rif (c).
Regarding "Gedudi," in his first explanation Rashi explains that "Gedudi"
refers to a pool that has high edges. If the pool does not have high edges,
that means that the bottom of the pool rises near the edge. There is
concern that one will dig his toes into the dirt on the bottom, causing the
dirt and water to be kneaded together. (According to this explanation, it
would seem that even without lifting one's feet from the floor of the pool,
it is not permitted to use such a pool on Shabbos, since the problem is one
(b) According to Rashi's second explanation, "Gedudi" refers to a rim
around the edges of the pool that gives the pool the appearance of a large
vessel. No one will confuse swimming in a vessel with swimming in a river
(which is forbidden, lest one make a flotation device). If the pool has no
rim, it resembles a river, and therefore one may only go in if he does not
actually swim or float (that is, he keeps his feet on the floor of the
(c) The RIF explains that "Oker" means to uproot *water* from the pool. If
the pool has no rim (and is level with the rest of the Chatzer), one may
not splash water out of the pool. The water which splashes out of the pool
will make is look like a rivulet and give the impression that it is
permitted to swim in a river -- an act which the Rabanan prohibited on
Shabbos. However, if the pool has a rim, the rim surrounds the pool-water
and prevents the water from splashing out of the pool. It does not look
like the pool is part of a rivulet; it clearly appears as an independent
vessel. Therefore, it is permissible to swim normally because it will not
look like one is swimming in a river.
(Apparently, Rebbi Zeira's doubt was whether it is permitted to splash even
when there is a rim, and the conclusion is that it is indeed permissible.
It is not clear why it should not have been permissible. Alternatively, the
RIF permits swimming in a pool with a rim since the rim "surrounds" its
waters ("Mehadri Lehu") making it distinct from the water which splashes
out from it. This is why it cannot be confused with a rivulet. If this is
the Rif's intention, it is more easily understood why Rebbi Zeira
entertained the possibility that it is prohibited to splash in a pool with
a rim; he thought that perhaps the rim does not set the pool clearly apart
from the water which splashes from it. It is also apparent from the
Gemara's conclusion, according to the Rif, that one *may* swim in a pool
without a rim which stands in a Chatzer, as long as he does *not splash*.
However, this Halachah is not clearly cited by the Poskim -- M. Kornfeld.)
2) PUTTING COLD WATER IN A HOT VESSEL WITHOUT INTENTION TO HARDEN IT
QUESTION: Rav Ada Bar Masna understands the Mishnah (41a) to be saying that
when the hot kettle has been emptied of its water, it is permissible to
pour water into the kettle in order to warm it, even though pouring cold
water into a hot vessel tends to harden the vessel. Since one does not
intend to harden the vessel, it is a Davar sh'Ein Miskaven and is
permissible (according to Rebbi Shimon).
3) HARDENING A METAL UTENSIL
However, even Rebbi Shimon agrees that unintentionally performing a
Melachah is *forbidden* when it will *inevitably occur* as a result of
one's action ("Pesik Resha;" see Insights 29:2)! If so, why is it permitted
to pour cold water in the hot kettle in order to warm the water, when
hardening of the vessel will *definitely* occur as a result of pouring in
(a) TOSFOS (DH Meicham) says that it is *not* certain that the utensil will
(b) The RA'AVAD (cited by the Ramban in Milchamos Hashem) answers that our
Gemara does now know that Rebbi Shimon agrees that in cases of Pesik Resha,
even a Davar sh'Ein Miskaven is forbidden. Our Gemara assumed that he
permits a Davar sh'Ein Miskaven even when it is a Pesik Resha. The Ramban
rejects this explanation.
(c) The RITVA and RAMBAN explain that our Gemara is discussing a utensil
that already underwent an extensive hardening process (and it is doubtful
whether it can be hardened further).
(d) Alternatively, they suggest, it was doubtful whether the heat at which
the utensil was heated was enough to enable it to be hardened when cold
water is poured into it.
QUESTION: RASHI (DH Ela Shi'ur) says that a utensil is only hardened
(through heating it to a very high temperature and then pouring cold water
into it) when it is *completely* filled with cold water. If so, when Rav
Ada Bar Masna (41a) said that it is permissible to pour a large quantity of
cold water into a hot vessel in order to warm the water, and the Gemara
asked that it should be forbidden because of hardening, the Gemara should
have simply answered that we are discussing a case when he did not
completely fill the utensil!
In addition, Abaye states that if one emptied a hot vessel, one may not put
"any cold water in it at all" because of hardening. Why does he prohibit
putting any cold water in, if it will only be hardened when it is
(a) TOSFOS YESHANIM says that according to Rashi, the words "Kol Ikar"
("any [cold water] at all") are a mistake and do not belong in the Gemara.
(See also TOSFOS YESHANIM at the end of the page, who cites Maharash
me'Mirzburg who understands the Gemara differently from Rashi.)
(b) Rashi may have learned that the Gemara here, according to Rav, does not
agree with the earlier Gemara that assumes that hardening can be
accomplished with even a small amount of cold water.