סימן פ סעיף יד
מֻתָּר לִתֵּן שֻׁמָּן קָרוּשׁ עַל מַאֲכָל חַם, אַף עַל פִּי שֶׁהוּא נִימּוֹחַ. הַשֶּׁלֶג וְהַבָּרָד, אֵין מְרַסְּקִין אוֹתָן בְּיָּדַיִם, דְּהַיְנוּ לְשַׁבְּרָם לַחֲתִיכוֹת, כְּדֵי שֶׁיָּזוּבוּ מֵימֵיהֶם. אֲבָל נוֹתֵן הוּא לְתוֹךְ הַכּוֹס שֶׁל יַיִן אוֹ מַיִם כְּדֵי לְצַנְּנָם וְהֵם נִימּוֹחִים מֵאֲלֵיהֶם וְאֵינוֹ חוֹשֵׁשׁ. וְצָרִיךְ לִזָּהֵר בַּחֹרֶף, שֶׁלֹּא יִטֹּל יָדָיו בְּמַיִם שֶׁיֵּשׁ בָּהֶם שֶׁלֶג אוֹ בָּרָד. וְאִם יִטּוֹל, יִזָּהֵר שֶׁלֹּא יִדְחֲקֵם בֵּין יָדָיו, שֶׁלֹּא יְהֵא מְרַסֵּק. וּמֻתָּר לִשְׁבּוֹר קֶרַח כְּדֵי לִטּוֹל מַיִם מִתַּחְתָּיו. וּלְהַשְׁתִּין בְּתוֹךְ הַשֶּׁלֶג, טוֹב לִזָּהֵר אִם אֶפְשָׁר. וְכֵן יֵשׁ לִזָּהֵר, שֶׁלֹּא לְהַשְׁתִּין עַל גַּבֵּי טִיט אוֹ לְתוֹךְ עָפָר תִּחוֹחַ (שיח שכ).
It is permitted to place congealed fat upon hot food57This is permitted only in a keli sheini [Misgeres Hashulchan]. (see Kitzur Shulchan Aruch, Chapter 72) even though it melts.58Shulchan Aruch 318: 16. Our custom is to be stringent and not to do this even when the fat will not ever heat up to yad soledes. We are lenient, however, when necessary. [For example, oneg Shabbos (Shaarei Tziyon 318: 133), or when a guest arrives (see Rema 333: 1) etc.]. (see Rema 318: 16 and Mishnah Berurah) You may not crush snow or hail by hand,59The Kitzur Shulchan Aruch permits placing congealed fat upon hot foods because the melting is accomplished by itself, and not directly by anyone’s action. Fat and ice have almost identical Halachos in this regard. (see Mishnah Berurah) breaking them into pieces so that their water oozes out; but you may put [ice] into a cup of wine or water to chill it, letting the ice melt of itself.60Mishnah Berurah 320: 33 rules that crushing ice is forbidden because it is similar to creating water. Another reason it is forbidden is because it might lead one to think it is permissible to squeeze fruits for juice (Rambam). Therefore, merely putting an ice cube in a cup of wine or water, is permitted because the Sages saw no reason to enact such a prohibition. (Vilna Gaon) In the winter, you should be careful not to wash your hands with water containing snow or hailstones. If you did, you should be careful not to squeeze them with your hands, in order not to crush them. It is permissible to break ice in order to take water from underneath.61Because the water is not derived as a result of the ice. (Beis Yosef, Vilna Gaon) Urinating in snow should be avoided if possible.62Because the snow will surely melt as a direct result of this act. However, if there is a problem about finding another place, it is permissible to urinate on snow. (Mishnah Berurah) Likewise, you should be careful not to urinate on mud or soft dirt.63Because of the melachah of losh (לָשׁ), kneading. (see Peri Megadim (321: 19) and Chayei Adam 19: 4)
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.)