סימן פו סעיף ד
הָרוֹחֵץ צָרִיךְ לִזָּהֵר שֶׁלֹּא לִסְחוֹט שְׂעָרוֹ. וְכֵן צָרִיךְ לִזָּהֵר שֶׁלֹּא לָשׁוּט, כִּי אָסוּר לָשׁוּט בַּשַׁבָּת וּבְיוֹם טוֹב. וְכֵן אָסוּר לְהָשִׁיט אֵיזֶה דָּבָר, כְּגוֹן הַקִּסְמִין שֶׁעַל הַמָּיִם. וְאִם רוֹחֵץ בְּמָקוֹם שֶׁאֲסוּרִין לְטַלְטֵל, צָרִיךְ עוֹד לִזָּהֵר, שֶׁקֹּדֶם צֵאתוֹ יָסִיר תְּחִלָּה הַמַּיִם שֶׁעַל גּוּפוֹ וְשַׂעֲרוֹתָיו, וִינַגְּבֵם יָפֶה שֶׁלֹּא יִשָּׁאֲרוּ עָלָיו מַיִם וְיוֹצִיאֵם מֵרְשׁוּת לִרְשׁוּת. וְגַם בַּנָּהָר עַצְמוֹ צָרִיךְ לִזָּהֵר, שֶׁלֹּא יִשָּׂא אֶת הַמַּיִם שֶׁעָלָיו, אַרְבַּע אַמּוֹת, כִּי הַנָּהָר הוּא כַּרְמְלִית. וּלְפִי שֶׁאֵין כֻּלָּם יוֹדְעִים לִזָּהֵר, עַל כֵּן נִתְפַּשֵּׁט הַמִּנְהָג בִּמְדִינוֹת אֵלּוּ, שֶׁלֹּא לִרְחוֹץ כְּלָל בַּשַׁבָּת אֲפִלּוּ בְּצוֹנֵן, כִּי אִם לְצֹרֶךְ מִצְוָה, כְּגוֹן אִשָּׁה נִדָּה (כִּדְלְקַמָּן סִימָן קס"ב סָעִיף ז') וְאִישׁ לְקִרְיוֹ.
If you bathe, be careful not to squeeze your hair.10Washing itself is permitted because squeezing water from the hair is only a derabanan prohibition, since you have no need for the water squeezed from the hair. [Mishnah Berurah 326: 25–28, see also Igros Moshe o.c. 133] Drying the hair is also permitted. [v. Minchas Shabbos] Avnei Neizer (o.c. 157) rules not to wash hair with your hands lest you inadvertently pull out some hairs. [v. Shemiras Shabbos Kehilchasah, Ketzos Hashulchan] Also take care not to swim because it is prohibited to swim on Shabbos and Yom Tov.11[Maseches Beitzah 36, Shulchan Aruch 339: 1] The author later writes that it is the custom not to bathe in an ocean or pool even without swimming. [v. Mishnah Berurah 326: 21] It is also forbidden to make things float, such as wood chips, on top of the water.12[Yerushalmi, Shulchan Aruch 339: 6] This prohibition applies only in a river, lake or ocean, but in a tub or pool it is permitted. [Bach, Magein Avraham, Mishnah Berurah] If you bathe in a place where it is forbidden to carry, you must also take care before leaving [the water], to first remove the water from your body and hair, and dry yourself well, so that no water remains on you, which you would be carrying from one domain into another.13[Maseches Shabbos 141] Similarly, care must be taken not to carry the water four amos in a karmelis. [Shulchan Aruch 326: 7] Similarly, in the river itself, you must take care not to carry the water which is on you four amos, because the river is considered a karmelis.14Peri Megadim, Mishnah Berurah 326: 22. Some argue that the Shulchan Aruch does not agree and allows walking within the river because the water on your body is considered one with the water in the river and is not considered as being carried from one place to another. [Minchas Pittim] Also, your intent while walking is not to carry the water and is, therefore, permitted. Also, the amount on your body is negligible (less than a revi’is) which Meiri permits even out of the water. [Eretz Tzvi 72] Since not everyone knows to be careful, therefore, it has become the prevailing custom in these regions not to bathe at all on Shabbos even in cold water, except for the purpose of a mitzvah, such as a woman after menstruation, (as discussed further, Chapter 162, paragraph 7) or a man after a nocturnal emission.
תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)