Positive commandment · Mitzvat Aseh #159 of 613
To rest on the first day of Pesach
לשבות בראשון של פסח
The verse · Shemot 12:16
וּבַיּוֹם הָרִאשׁוֹן מִקְרָא־קֹדֶשׁ וּבַיּוֹם הַשְּׁבִיעִי מִקְרָא־קֹדֶשׁ יִהְיֶה לָכֶם כׇּל־מְלָאכָה לֹא־יֵעָשֶׂה בָהֶם אַךְ אֲשֶׁר יֵאָכֵל לְכׇל־נֶפֶשׁ הוּא לְבַדּוֹ יֵעָשֶׂה לָכֶם
“And on the first day there shall be a holy gathering, and on the seventh day there shall be a holy gathering to you; no manner of work shall be done on them, save that which every person must eat, that only may be done by you.”
The Rambam’s words
To rest on the first day of Pesach, as [Exodus 12:16] states: "And on the first day, it shall be a sacred holiday."
לשבות בראשון של פסח, שנאמר: "וביום הראשון, מקרא קודש" (שמות יב,טז).
Why · Sefer HaChinuch #297
Resting on the first day of Pesach
“It is from the roots of the commandment [that it is] in order that we think about the content of the holiday in the miracle that was done for us on it, and that we praise and laud in our thoughts the One, blessed be He, Who commanded us about it and did miracles for us at this time.”
Who & when
“And [it] is practiced in every place and at all times by males and females.”
Where in the Mishneh Torah
Hilchot Rest on a Holiday הלכות שביתת יום טוב