Not to leave the Paschal Offering fat overnight

This mitzvah forbids allowing the sacrificial fats (cheilev) of the Korban Pesach to remain until morning. They must be consumed on the altar the night they are offered. Rambam (Hilchot Korban Pesach 1:6–7; Hilchot Ma’aseh HaKorbanot 4:2) codifies that failure to burn them on time transgresses this mitzvah.

Sefer HaChinuch (Mitzvah 488) explains that sacrifices must be completed promptly, showing zeal in the service of Hashem. Leaving fats overnight suggests negligence or disregard for sanctity. The Talmud (Pesachim 59b) emphasizes the Pesach’s unique urgency, tied to the redemption it commemorates. Rashi (Ex. 23:18) notes that “My festive offering” refers specifically to the Pesach, highlighting its centrality. Ramban adds that this mitzvah parallels the prohibition of notar (leaving sacrificial meat past its time), ensuring full devotion without delay.

Commentary & Classical Explanation:

• Rambam (Korban Pesach 1:6–7): Prohibits leaving sacrificial fats until morning.
• Rambam (Ma’aseh HaKorbanot 4:2): Details obligation to burn fats same night.
• Sefer HaChinuch (Mitzvah 488): Teaches zeal and promptness in avodat Hashem.
• Talmud (Pesachim 59b): Links timing to Pesach’s urgency and redemption.
• Rashi (Ex. 23:18): Identifies “My festive offering” as Pesach.
• Ramban (Ex. 23:18): Compares to notar prohibitions, extending sanctity.

Contrast with Notar of Sacrificial Meat (Mitzvah 395):

• Mitzvah 406 prohibits leaving fats; Mitzvah 395 prohibits leaving meat.
• Rambam explains both guard against disrespect of holy portions.
• Talmud (Pesachim 84b) connects both prohibitions under the principle of zeal (zerizut) in korbanot.

Parallel to Burning Leftover Sacrifices (Mitzvah 398):

• Just as leftovers must be destroyed by fire, the fats must be offered without delay.
• Sefer HaChinuch explains this ensures the korban cycle concludes in holiness, without laxity.
• Ramban highlights both teach that holiness demands timeliness.