The law of Pesach Sheini was inspired by a group of men who had been tamei, contaminated, by a corpse. They came forth and complained that they had not been permitted to share in the mitzvah of Korban Pesach. Chazal debate the identity of these men. Rabbi Yishmael says that they were the ones who were carrying Yosef’s coffin. Rabbi Yitzchak claims that they had become tamei as a result of tending to a “meis mitzvah,” a corpse who has no one to look after him. Rabbi Akiva opines that they were Aharon’s cousins, Mishael and Eltsafan, who had become tamei by their contact with the bodies of Nadav and Avihu.
The Sefas Emes notes the attitude of these men, especially in contrast with that of the rest of Klal Yisrael. These men felt dejected when they were not included in one mitzvah, Korban Pesach, while Bnei Yisrael did not seem to complain about being deprived of the mitzvah of Korban Pesach the entire forty years that they were in the desert.
The Sefer Ha’chinuch gives rationales for the dispensation of Pesach Sheini. The explanations are related to the sanctity and pre-eminence of Pesach as a foundation of our belief in Hashem, His Torah and Moshe Rabbeinu, the father of all Neviim. Pesach is distinguished by its alluding signs to the splitting of the Red Sea, one of the most notable miracles of all time, and to Hashem as the G-d of history, Who sustains us constantly. We may wonder why the Torah is so insistent that we offer a second korban. What about matzo? Is the mitzvah of eating matzo to be ignored? Does the mitzvah of matzo not imply the same concept as Korban Pesach?
These two mitzvos are distinct from one another. Korban Pesach signifies our original preparation and yearning for Pesach. In Egypt, Bnei Yisrael began involving themselves in the preparation as early as the tenth of Nissan. One who does not prepare himself for the moment of redemption is given yet another chance to participate. On the other hand, one who has the opportunity to leave Egypt and does not do so because he was “busy” or “tamei”, has lost his chance. Matzo symbolizes the actual redemption from Egypt. A Jew who is aware of the redemption, but cannot mark it at the designated time, loses his opportunity. There are certain things for which one simply cannot be late – one of them is his own redemption.