Talmud zu Schemot 12:29

We have stated “the eating of the Passover sacrifice”. Some people do not formulate “the eating of the Passover sacrifice”. Who formulates “the eating of the Passover sacrifice”? The Sages. Who does not formulate “the eating of the Passover sacrifice”? Rebbi Eliezer.¹³⁵For the Sages, the obligation of eating the Passover sacrifices lasts during the entire Seder night; the limitation to the first half of the night is a Rabbinical ordinance. According to Rebbi Eliezer [and Rebbi Eleazar ben Azariah in the Babli, Berakhot 9a], there is a Biblical prohibition of celebrating the Exodus after midnight. (Cf. the discussion in the author’s The Scholar’s Haggadah, Northvale NJ 1995, pp. 263–264.)
Rebbi Eliezer’s argument goes as follows: The Bible prescribes that the Passover sacrifice should be eaten “in that night.” It also reports that the death of the Egyptian firstborn was “in the middle of the night”. Since the second occurrence of “night” is qualified by “middle” but the first is left indeterminate, and we subscribe to the opinion that, unless explicitly given otherwise, words in the Pentateuch have an invariable meaning, the first occurrence must also mean “midnight.” The Sages follow Rebbi Aqiba in pointing out that the first Passover had to be eaten “in a hurry”, the hurry of the Exodus that happened only the following day. Hence, the notion of “night” here is opposed to “day” and not restricted to the first half. What is the reason of Rebbi Eliezer? It is written here (Ex. 12:8) “in the night”, and it is written there (Ex. 12:29) “in the night”. Just as there it means midnight, so also here it means midnight. Rebbi Ḥuna¹³⁶This is the form in which the name of the Galilean Amora R. Ḥuna appears most frequently in the Yerushalmi. It is probable that the Babylonian Amora Rav Huna (הוּנא) also originally was called חוּנא “the gracious one”, but in Babylonia every ח was pronounced as ה.
Rebbi Ḥuna points out that, since we are agreed that this Mishnah and the following one deal only with Rabbinical ordinances, the mention of the Passover sacrifice is impossible since, by Rabbinical ordinance, the Passover sacrifice is ritually impure after midnight, for the same reason that voluntary offerings cannot be eaten after midnight as explained in the next Halakhah. Here is another fundamental difference between the Yerushalmi and the Babli. According to the Yerushalmi both in Berakhot and in Pesaḥim (37d), the prohibitions mentioned in the Mishnah are Rabbinical. But the Babli in both cases (Berakhot 9a, Pesaḥim 120b) refers only to the opinions of Rebbis Eliezer and Eleazar ben Azariah that the prohibition is Biblical. says: “The eating of the Passover sacrifice” cannot be here even for the Sages since we have stated (Pesaḥim 10:9) “the Passover sacrifice after midnight makes one’s hands impure.”¹³⁹This is the reading of the שׂרידי ירוּשלמי from the Cairo Genizah. The Leyden manuscript and the printed editions have קדשים קלים “simple sacrifices”. Zachariah Frankel already conjectured that the correct reading must be the one before us, as will be explained now.
There were four kinds of animal sacrifices in the Temple. Of certain sacrifices of atonement, only the blood was sprinkled on the altar; the rest was burnt outside the Temple precinct. The flesh of the עוֹלה, “holocaust” (totally burnt), was all burnt on the altar. The usual sacrifices of atonement had to be eaten by male Cohanim in the Temple precinct, except that blood, fat, and certain organs had to be burnt on the altar. These sacrifices are called “holiest of holies” and had to be consumed during the day of sacrifice or the following night. Family sacrifices, שׁלמים, “peace”, or “payment”, or “wholeness” sacrifices, were eaten by the family of the votary (except for the blood and fat, which was burnt on the altar, and certain parts which were to be eaten by priestly families.) These family sacrifices were called “simple sacrifices”; most of them had to be eaten during two days and the intervening night. The only “simple sacrifices” to be eaten during one day were thanksgiving sacrifices and the sacrifice of the Nazir at the end of his votary period when he cut his hair. Hence, all “holiest of holies” sacrifices are covered by our Mishnah but only a minority of “simple sacrifices”. There might be some justification for the reading “simple sacrifices” referring to the obligation of laity only who never ate “holiest of holies”; but then no special determination would be necessary.

And it came to pass at midnight, that the Lord smote all the first-born in the land of Egypt,²Ex. 12, 29. etc.; and it is written, For all the first-born among the children of Israel are Mine, both men and beast; on the day that I smote all the first-born in the land of Egypt, I sanctified them for Myself.³Num. 8, 17. R. Joḥanan said: Although He smote them with the plague of death at midnight, the souls writhed within them until morning. A common proverb says, ‘If you give a morsel of bread to a child, inform his mother’.⁴Cf. Beẓah 16a (Sonc. ed., p. 81) where it is quoted, not as a proverb, but as a saying of Rabban Simeon b. Gamaliel. Likewise, the Holy One, blessed be He, said, ‘I will inform My children of the death by choking⁵GRA’s emendation of a verb in the text meaning ‘which silences’. of which their enemies are dying. Let their souls await the morning [before expiring], so that My children shall look upon [the fate of] their enemies’.

For this reason⁸That most of the month contained festival days. no supplications⁹This refers in particular to the prayer, ‘And He, being merciful’, etc. (P.B., pp. 57-65). are offered on any of the days of Nisan and there is no fasting until Nisan has passed. The only exception is [the fast of] the firstborn who fast on the eve of Passover.¹⁰In thanksgiving for the deliverance of the Israelite firstborn on Passover eve when Egypt’s firstborn perished (Ex. 12, 29). The very pious also fast on that day on account of the unleavened bread, in order that they shall begin to eat it¹¹On the evening preceding the fifteenth of Nisan. Lit. ‘that they shall enter it’. with relish.¹²In honour and appreciation of the commandment. Scholars fast on Mondays and Thursdays [throughout the year] on account of the desecration of the name of God¹³By the heathens who destroyed Jerusalem. and for the honour of the Temple which was burnt.