To not do work on the day of the holiday of Shavuot: To not do work on the day of [Shavuot] — which is the sixth day of Sivan, as it is stated (Leviticus 23:15-16), “And you shall count for yourselves from the morrow of the Shabbat, etc. you shall count fifty days, etc.” And the understanding of “from the morrow of the Shabbat,” is meaning to say, the morrow of the first holiday of Pesach, about which it was speaking first. As if it was the Shabbat of creation (the seventh day of the week) — if so, it will not have informed us which. And it comes out that the fifty days end on the sixth of Sivan. How is this? Fifteen days from Nissan, which is always full (consisting of thirty days); and twenty-nine days of Iyar, which is always lacking (consisting of twenty-nine days); and six days of Sivan — behold, [that is] fifty. And this fiftieth day — which was the day that the Torah was given — is the holiday of the Assembly (atseret), and it is also called the holiday of Shavuot (Weeks). And it is also written at the end of the section about this glorious day (Leviticus 23:21), “all work of labor shall you not do” — we have already written that any labor that is not for the needs of food for the soul is called, work of labor.
The root of the commandment of this appointed time is hinted in the commandment of the counting of the omer (Sefer HaChinukh 306) — and take it from there.
And I have written some of its laws — as is my custom — in the commandment of the resting from work on the first day of Pesach in this Order (Sefer HaChinukh 298). And there is no need to write at length about the rest of the appointed times of the year. As the six well-known days of the appointed times of the year — and they are the first and seventh [days] of Pesach, the first and eighth days of the Holiday [Sukkot], Atseret [Shavuot] and Rosh Hashanah — all have one law for all of their dispensations and all of their prohibitions. And the elucidation of all of its laws at length is in the tractate that is built on this, and that is Tractate Beitzah. (See Tur, Orach Chaim 496.)
שֶׁלֹּא לַעֲשׂוֹת מְלָאכָה בְּיוֹם חַג שָׁבוּעוֹת – שֶׁלֹּא לַעֲשׂוֹת מְלָאכָה בְּיוֹם עֲצֶרֶת, שֶׁזֶּהוּ יוֹם שִׁשִּׁי בְּסִיוָן, שֶׁנֶּאֱמַר (ויקרא כג טו טז) וּסְפַרְתֶּם לָכֶם מִמָּחֳרַת הַשַּׁבָּת וְגוֹ' תִּסְפְּרוּ חֲמִשִּׁים יוֹם וְגוֹ'. וּפֵרוּשׁ מִמָּחֳרַת הַשַּׁבָּת כְּלוֹמַר, מָחֳרַת יוֹם טוֹב רִאשׁוֹן שֶׁל פֶּסַח, שֶׁבּוֹ דִּבֵּר תְּחִלָּה, דְּאִי בְּשַׁבַּת בְּרֵאשִׁית אִם כֵּן לֹא יוֹדִיעֵנוּ אֵיזֶהוּ. וְנִמְצָא, שֶׁחֲמִשִּׁים יוֹם כָּלִים בְּשִׁשָּׁה בְּסִיוָן, כֵּיצַד? חֲמִשָּׁה עָשָׂר יָמִים מִנִּיסָן שֶׁהוּא מָלֵא לְעוֹלָם, וְעֶשְׂרִים וְתִשְׁעָה מֵאִיָּר שֶׁהוּא חָסֵר לְעוֹלָם, וְשִׁשָּׁה מִסִּיוָן, הֲרֵי חֲמִשִּׁים. וְיוֹם הַחֲמִשִּׁים זֶה, שֶׁהָיָה יוֹם שֶׁנִּתְּנָה בּוֹ תּוֹרָה, הוּא חַג הָעֲצֶרֶת, וְנִקְרָא גַּם כֵּן חַג הַשָּׁבוּעוֹת. וְכָתוּב בְּסוֹף הַפָּרָשָׁה עַל זֶה הַיּוֹם הַנִּכְבָּד כָּל מְלֶאכֶת עֲבֹדָה לֹא תַעֲשׂוּ. כְּבָר כָּתַבְנוּ כִּי מְלֶאכֶת עֲבוֹדָה נִקְרֵאת כָּל מְלָאכָה שֶׁאֵינָהּ לְצֹרֶךְ אֹכֶל נֶפֶשׁ.
To not do work on the day of the holiday of Shavuot: To not do work on the day of [Shavuot] — which is the sixth day of Sivan, as it is stated (Leviticus 23:15-16), “And you shall count for yourselves from the morrow of the Shabbat, etc. you shall count fifty days, etc.” And the understanding of “from the morrow of the Shabbat,” is meaning to say, the morrow of the first holiday of Pesach, about which it was speaking first. As if it was the Shabbat of creation (the seventh day of the week) — if so, it will not have informed us which. And it comes out that the fifty days end on the sixth of Sivan. How is this? Fifteen days from Nissan, which is always full (consisting of thirty days); and twenty-nine days of Iyar, which is always lacking (consisting of twenty-nine days); and six days of Sivan — behold, [that is] fifty. And this fiftieth day — which was the day that the Torah was given — is the holiday of the Assembly (atseret), and it is also called the holiday of Shavuot (Weeks). And it is also written at the end of the section about this glorious day (Leviticus 23:21), “all work of labor shall you not do” — we have already written that any labor that is not for the needs of food for the soul is called, work of labor.
שֹׁרֶשׁ מִצְוַת הַמּוֹעֵד הַזֶּה רָמוּז בְּמִצְוַת סְפִירַת הָעֹמֶר שֶׁבְּסֵדֶר זֶה (מצוה שו), וְקָחֶנּוּ מִשָּׁם.
The root of the commandment of this appointed time is hinted in the commandment of the counting of the omer (Sefer HaChinukh 306) — and take it from there.
וְדִינֶיהָ כָּתַבְתִּי קְצָתָם כְּמִנְהָגִי בְּמִצְוַת שְׁבִיתַת מְלָאכָה בְּיוֹם רִאשׁוֹן שֶׁל פֶּסַח שֶׁבְּסֵדֶר זֶה, וְאֵין צֹרֶךְ לְהַאֲרִיךְ בִּשְׁאָר יְמֵי מוֹעֲדֵי הַשָּׁנָה, כִּי שֵׁשֶׁת יְמֵי הַמּוֹעֲדִים הַיְּדוּעִים, וְהֵם, רִאשׁוֹן וּשְׁבִיעִי שֶׁל פֶּסַח וְרִאשׁוֹן וּשְׁמִינִי שֶׁל חָג, וַעֲצֶרֶת וְרֹאשׁ הַשָּׁנָה, דִּין אֶחָד לְכֻלָּם לְכָל הֶתֵּרָן וּלְכָל אִסּוּרָן. וּבֵאוּר כָּל דִּינֶיהָ בַּאֲרֻכָּה בַּמַּסֶּכְתָּא הַבְּנוּיָה עַל זֶה, וְהִיא מַסֶּכֶת בֵּיצָה [א"ח סימן תצו].
And I have written some of its laws — as is my custom — in the commandment of the resting from work on the first day of Pesach in this Order (Sefer HaChinukh 298). And there is no need to write at length about the rest of the appointed times of the year. As the six well-known days of the appointed times of the year — and they are the first and seventh [days] of Pesach, the first and eighth days of the Holiday [Sukkot], Atseret [Shavuot] and Rosh Hashanah — all have one law for all of their dispensations and all of their prohibitions. And the elucidation of all of its laws at length is in the tractate that is built on this, and that is Tractate Beitzah. (See Tur, Orach Chaim 496.)