סימן עח סעיף א
כְּשֶׁמּוֹסִיפִין בַּשַׁבָּת, יְכוֹלִין לִקְרֹת כֹּהֵן אוֹ לֵוִי לְאַחֲרוֹן, כֵּיוָן שֶׁכְּבָר הִשְׁלִימוּ שִׁבְעָה גַּבְרֵי. וְגַם שֶׁהוּא הָאַחֲרוֹן מֵעִקַּר הַקְּרוּאִים (חוּץ מִן הַמַּפְטִיר) וְכֵן הַמַּפְטִיר יְכוֹלִין לִקְרֹת כֹּהֵן אוֹ לֵוִי, וַאֲפִלּוּ כֹּהֵן אֶחָד לְאַחֲרוֹן וְכֹהֵן אֶחָד לְמַפְטִיר, יְכוֹלִין לִקְרוֹת, כֵּיוָן שֶׁהַקַּדִּישׁ מַפְסִיק בֵּינֵיהֶם. וּבְשִׂמְחַת תּוֹרָה שֶׁמּוֹצִיאין שְׁלשָׁה סִפְרֵי תּוֹרָה, יְכוֹלִין לִקְרוֹת כֹּהֵן אֶחָד לַחֲתַן תּוֹרָה וְאֶחָד לַחֲתַן בְּרֵאשִׁית וְאֶחָד לְמַפְטִיר, כֵּיוָן שֶׁכָּל אֶחָד קּוֹרֵא בְּסֵפֶר תּוֹרָה אַחֵר. אֲבָל בְּרֹאשׁ חֹדֶשׁ טֵבֵת שֶׁחָל לִהְיוֹת בְּשַׁבָּת, אַף עַל פִּי שֶׁמּוֹצִיאִין גַּם כֵּן שְׁלשָׁה סִפְרֵי תּוֹרָה, אֲפִלּוּ אִם רוֹצִים לִקְרוֹת בַּסֵּפֶר תּוֹרָה הָרִאשׁוֹן שְׁמֹנָה גַּבְרֵי, אֵין רַשָּׁאִין לִקְרוֹת לְהַכֹּהֵן שֶׁיִּהְיֶה הַשְּׁמִינִי, כֵּיוָן שֶׁעֲדַיִן אֵין מַשְׁלִימִין הַקְּרִיאָה בְּסֵפֶר זֶה. וְהַמַּשְׁלִים הוּא בַּסֵּפֶר הַשֵּׁנִי שֶׁקּוֹרִין בּוֹ פָּרָשַׁת רֹאשׁ חֹדֶשׁ וְאָז יְכוֹלִין לִקְרוֹתוֹ. וְכֵן הַדִּין בְּשַׁבָּת שְׁקָלִים וּפָרָשַׁת הַחֹדֶשׁ כְּשֶׁהֵן בְּרֹאשׁ חֹדֶשׁ (סִימָן קל"ה ובסד"ה).
When aliyahs1One who is called to read the Torah is called an oleh. The privilege of being called to the Torah is referred to as an aliyah. are added on Shabbos2See Maseches Megillah 21a. On Shabbos there must be no less than seven aliyahs. However, if there are present those who are obligated to have an aliyah, additional aliyahs may be added. a Kohen or Levi may be called for the last aliyah, since the requirement of calling seven men was fulfilled, and also because it is the last of the main aliyahs except for the maftir. Similarly, for maftir, a Kohen or Levi may be called. It is even permitted to call one Kohen for the last aliyah and one Kohen for maftir. They may be called [in this situation] since the kaddish intervenes between them. On Simchas Torah when three sifrei Torah are taken out, one Kohen may be called as Chasan Torah, [the groom of the Torah] and one as Chasan Bereishis, [the groom of Bereishis] and one for maftir, since each one reads from a different seifer Torah. But when Rosh Chodesh Teivis occurs on Shabbos, even though three sifrei Torah are taken out,3One for Shabbos, one for Chanukah, and one for Rosh Chodesh. even if they want to call eight men to the first seifer Torah, it is not permitted to call the Kohen to be the eighth one,4This ruling is in accord with the second opinion mentioned in Rema 135: 10. If, however, the Kohen went up to the Torah, we may rely on the others who rule that a Kohen or Levi may be called even after the required aliyahs. If this happens, it is preferable to call a Levi after the Kohen and then a Yisrael. See Mishnah Berurah 135: 37. This is done in order to avoid casting doubt on the Kohen’s lineage. See Kitzur Shulchan Aruch in the following Halachah. since as yet [the required reading] was not completed in this seifer. The reading is completed in the second seifer in which the portion of Rosh Chodesh is read, and then a Kohen may be called. The same law applies to Shabbos Shekalim and to Parshas Hachodesh when they occur on Rosh Chodesh.
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.)