PESACHIM 96 (20 Tishrei) - Dedicated by Al and Sophia Ziegler of Har Nof, Jerusalem, and their son Jared, in loving memory of Al's mother, Chaya bas Berel Dov Ziegler, on the day of her Yahrzeit - and that her grandson Jared may be Zocheh to build a Bayis Ne'eman b'Yisrael with his Kalah!

QUESTION: The Mishnah discusses the differences between Pesach Mitzrayim (the Pesach which the Jews celebrated when they left Egypt) and Pesach Doros (the festival of Pesach celebrated by all subsequent generations). The Mishnah says that one difference is that Pesach Mitzrayim was observed for one night, while Pesach Doros is celebrated for seven days and nights.
The Gemara explains that on both Pesach Mitzrayim and Pesach Doros, the obligation to eat the Korban Pesach applies only for one night. When the Mishnah says that Pesach Mitzrayim was observed for one night, and Pesach Doros is observed for seven days and nights, it refers to the prohibition of Chametz. During Pesach Mitzrayim, the prohibition of Chametz applied during the first night and day, while the prohibition of Chametz of Pesach Doros applies all seven days.
If Chametz was Asur on the night and the day of Pesach Mitzrayim, why does the Torah say that the Jewish people took Matzos with them because "they were rushed out of Mitzrayim and did not have time to make the dough into bread" (Shemos 12:39)? Even if they were not rushed out, they could not have made bread because Chametz was forbidden on that day. Why does the Torah imply that they would have made their dough into bread had they not been rushed out?
(a) The RAMBAN (Shemos 12:39) explains that the point of the verse in the Torah is to teach that had they not been rushed, they would have baked Matzah at home in Egypt, and not while in transit. The Torah relates that they baked the dough while they traveled because they were rushed out (and that is why it was still dough and not a finished product of Matzah). The emphasis is that they baked it on the road and not in Egypt. Had they not been rushed, they still would have baked Matzah, because Chametz was forbidden. However, they would have baked the Matzah in their homes and not while they traveled.
In a similar vein, the DA'AS ZEKENIM explains that when the Torah says that the Jewish people were rushed out of Mitzrayim, its intention is not to explain why the dough became Matzah and not Chametz. Chametz was forbidden, as the Gemara here says. Rather, the verse reveals why the only food that they brought with them was dough and nothing else. It was because they were rushed out and did not have time to prepare other provisions for themselves.
(b) The RAN (25b of the pages of the Rif) says that although it was forbidden to eat Chametz during Pesach Mitzrayim, it was not forbidden to own Chametz (Bal Yera'eh and Bal Yimatzei). The Jews intended to bake bread (Chametz) to eat on the following day, after Pesach (since the prohibition of Chametz applied for only one day that year). They were permitted to own Chametz on the first day of Pesach. (See TZELACH, Pesachim 116b, who challenges the Ran's explanation.)
(c) The HAFLA'AH (Panim Yafos, Bereishis 8:22 and Bamidbar 33:3) writes that before the Torah was given, the definition of "day" for Jews and non-Jews was the same -- the day preceded the night (the day started at daybreak). After the Torah was given, the definition of "day" changed for the Jews -- night precedes the day (the day starts at nightfall). Accordingly, when the Gemara says that it was forbidden to have Chametz for one full day, it refers to the day of the fourteenth of Nisan (when the Korban Pesach was slaughtered) and the night that followed that day. On the day the Jews actually left Egypt (the fifteenth of Nisan) no prohibition of Chametz applied at all. (Heard from Rav Kalman Weinreb, shlit'a, in the name of Rav Dovid Kronglass, zt'l.)
According to this explanation, the Mishnah -- which says that during Pesach Mitzrayim the prohibition of Chametz applied for one night -- does not contradict the Gemara which says that it means a whole day (day and night). When the Mishnah says "one night" it means that the time of the prohibition of Chametz which is common with Pesach Doros is only one night -- the first night. The Mishnah does not discuss the day before that night, since that is not common with Pesach Doros (because it was the day before Pesach.)
Similarly, the TZELACH (Pesachim 116b) proposes that with regard to Pesach Mitzrayim, "one day" refers to a day followed by the night. However, he defines a "day" in this manner for a different reason. The verse that the Gemara cites as the source for the prohibition of Chametz during Pesach Mitzrayim is written in a discussion of the Avodah of the Korban Pesach (Shemos 13:4-5, see Rashi there). In matters of Kodshim, the night follows the day (Chulin 83a). Hence, the prohibition of Chametz which is written in proximity to the discussion of the Korban Pesach refers to a "Kodshim-day," which begins at sunrise, with the day followed by the night.