סימן פ סעיף א
<small>(עִקַּר הַמְּלָאכוֹת שֶׁנֶּאֶסְרוּ לָנוּ לַעֲשׂוֹתָם בַּשַׁבָּת, כְּבָר נוֹדְעוּ לְרֹב בְּנֵי יִשְֹרָאֵל, וְלֹא נִכְתַּב כָּאן רַק מִדְּבָרִים שֶׁלֹּא נוֹדְעוּ לְרַבִּים וְהֵמָּה דְּבָרִים שְׁכִיחִים).</small><br>אָסוּר לְהִשְׁתַּמֵּשׁ לְאוֹר הַנֵּר דָּבָר שֶׁצָּרִיךְ עִיּוּן קְצָת, דְּגָזְרוּ רַבָּנָן, שֶׁמָּא יִשְׁכַּח וְיַטֶּה אֶת הַנֵּר, לְקָרֵב אֶת הַשֶּׁמֶן אֶל הַפְּתִילָה, וְיִתְחַיֵּב מִשּׁוּם מַבְעִיר וּשְׁנַיִם, מֻתָּרִין לִקְרוֹת מִתּוֹךְ סֵפֶר אֶחָד בְּעִנְיָן אֶחָד, שֶׁאִם יָבֹא אֶחָד לְהַטּוֹת, חֲבֵרוֹ יַזְכִּירֵהוּ. וּבַנֵּרוֹת שֶׁלָּנוּ שֶׁהָחֵלֶב אוֹ הַשַּׁעֲוָה כָּרוּךְ עַל הַפְּתִילָה, נוֹהֲגִין לְהַתִּיר. אַךְ צָרִיךְ לַעֲשׂוֹת אֵיזֶה הֶכֵּר, שֶׁלֹּא יָבֹא לִקְצֹץ רֹאשׁ הַפְּתִילָה שֶׁנַּעֲשֶׂה פֶּחָם. וּלְהָרַמְבַּ"ם, הֲוֵי אִסּוּר דְּאוֹרָיְתָא. וַאֲפִלּוּ עַל יְדֵי אֵינוֹ יְהוּדִי אָסוּר לִקְצוֹץ רֹאשׁ הַפְּתִילָה (סִימָן ער"ה רע"ח).
The principal melachos which we are forbidden to do on Shabbos are already known to most of the Jewish people. Thus, we will list only those things which are not generally known [to be forbidden] and are done in our daily activities.
It is forbidden to use the light of an oil lamp1Even if the oil lamp is placed very high and is quite inaccessible. (See Taz and Biur Halachah 275) for anything that requires concentration.2Reading portions of the prayers that are somewhat familiar to you is permitted. (Shulchan Aruch, 1 Mishnah Berurah) This is a rabbinic prohibition, lest you forget and tilt the lamp to draw the oil closer to the wick, thereby violating [the deoraisa3Deoraisa refers to something that is prohibited by the Torah. prohibition of] lighting a fire. Two people may read the same subject4Most poskim permit this only for such reading that is a mitzvah, such as Torah study or reciting Psalms. (Magein Avraham, Peri Megadim, Mishnah Berurah) from the same book together, for if one attempts to tilt the lamp, the other one will remind him. [Studying by the light of] our present day candles5Candles of superior quality are permitted, for they never need adjustment. (Mishnah Berurah) in which the wax or tallow adhere to the wicks, is permitted,6Many poskim disagree [Vilna Gaon] and it should be avoided where there is no particular necessity (Magein Avraham, Mishnah Berurah). All the poskim agree that wax and tallow candles are prohibited for reading in the synagogue or in other public places. (Peri Megadim, Mishnah Berurah) but you must make some sort of mark in order to remember not to snip off the charred end of the wick which, according to the opinion of the Rambam, is a deoraisa prohibition.7This prohibition is called mesakein manah, fixing a utensil [Vilna Gaon 514]. This is prohibited only when part of the charred wick is snipped off, but if the piece of charcoal on top is removed without removing a piece of the wick, there is no transgression. However, since most likely a piece of wick will be removed, many poskim prohibit it and this is our custom. (Mishnah Berurah 514) Even through a non-Jew, it is forbidden to snip off the tip of the wick.
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.)