The commandment of resting on the day of Rosh Hashanah: To rest from all work on the first day of the month of Tishrei, except for that which is specific for the needs of food for the soul, as it is stated (Leviticus 23:24), “On the seventh month, on the first day it shall be a shabbaton for you.” And the seventh month is the month of Tishrei, since Nissan is the new year for months and it is called the first in Scripture. And I wrote in the commandment of resting on the first day of Pesach (Sefer HaChinukh 297) that which they, may their memory be blessed, said, (Rosh Hashanah 2a), “This ‘shabbaton’ is a positive commandment.” And all the rest of the content of the commandment is as it is written there.
מִצְוַת שְׁבִיתָה בְּיוֹם רֹאשׁ הַשָּׁנָה – לִשְׁבֹּת מִכָּל מְלָאכָה חוּץ מִמַּה שֶׁמְּיֻחָד לְצֹרֶךְ אֹכֶל נֶפֶשׁ בְּיוֹם רִאשׁוֹן שֶׁל חֹדֶשׁ תִּשְׁרֵי, שֶׁנֶּאֱמַר (ויקרא כג כד) בַּחֹדֶשׁ הַשְּׁבִיעִי בְּאֶחָד לַחֹדֶשׁ יִהְיֶה לָכֶם שַׁבָּתוֹן, וְחֹדֶשׁ הַשְּׁבִיעִי הוּא חֹדֶשׁ תִּשְׁרֵי, לְפִי שֶׁנִּיסָן רֹאשׁ הַשָּׁנָה לֶחֳדָשִׁים, וְרִאשׁוֹן יִקָּרֵא בַּכָּתוּב, וְכָתַבְתִּי בְּמִצְוַת שְׁבִיתַת יוֹם רִאשׁוֹן שֶׁל פֶּסַח, (מצוה רצז) מָה שֶׁאָמְרוּ זִכְרוֹנָם לִבְרָכָה (ר"ה ב, א) הַאי שַׁבָּתוֹן עֲשֵׂה הוּא, וְכָל שְׁאָר עִנְיַן הַמִּצְוָה, כְּמוֹ שֶׁכָּתוּב שָׁם.
The commandment of resting on the day of Rosh Hashanah: To rest from all work on the first day of the month of Tishrei, except for that which is specific for the needs of food for the soul, as it is stated (Leviticus 23:24), “On the seventh month, on the first day it shall be a shabbaton for you.” And the seventh month is the month of Tishrei, since Nissan is the new year for months and it is called the first in Scripture. And I wrote in the commandment of resting on the first day of Pesach (Sefer HaChinukh 297) that which they, may their memory be blessed, said, (Rosh Hashanah 2a), “This ‘shabbaton’ is a positive commandment.” And all the rest of the content of the commandment is as it is written there.