Shemos, 12:21-23: “And Moshe called to all the Elders of Israel and said to them, ‘Draw forth (mishchu) and take yourselves one of the flock for your families, and slaughter the Pesach offering. You shall take a bundle of hyssop and dip it into the blood that is in the basin, and touch the lintel and the two doorposts with some of the blood that is in the basin, and as for you, no man shall leave the entrance of his house until morning. HaShem will pass through to smite Mitzrayim and He will see blood that is on the lintel and the two doorposts, and HaShem will pass over the entrance and He will not permit the destroyer to enter your houses to smite.
Rabbeinu Bechaye, Dh: Mishchu: “…Because the descent to Mitzrayim was through meshicha(drawing), as it says, “And they drew (veyimshechu) and brought out Yosef”…”
The Plague of the First-born was the last and most severe of all the Ten Plagues. There is a notable difference between the build up to this Plague and all the others. This is the only Plague where the Jewish people had to perform a Mitzva before the Plague took place. They were commanded to slaughter a sheep, dip its blood on the doorposts, and to eat the sheep with one’s family as part of the Korban Pesach. The ostensible reason for this was so that the Jewish people would have a merit to not be harmed by the Plague. The obvious question is why did they not need to do any kind of Mitzvos before any of the other Plagues? A simple answer is that this final plague was the main plague that actually enabled the Jews to finally leave Mitzrayim, whereas the others were more to teach the world about the existence of G-d. In order to merit actually leaving Mitzrayim, the Jews needed a merit, and so they were given this Mitzva.
However, questions remain – firstly, what was the significance of the details of this specific Mitzva that served as the key to enabling the Jews to finally leave Mitzrayim? In addition, the Chikrei Levasks that if the purpose of leaving was to have Mitzvos why wasn’t it enough to slaughter the sheep and dip the blood before the Plague, but to eat the Korban Pesach after the Plague – indeed, the reason for the Mitzva of eating the Korban Pesach is a remembrance that HaShem skipped over the houses of the Jews during the Plague – but that hadn’t even happened yet, so surely it would have made more sense to eat from the Korban after the Plague?
The Chikrei Lev makes a fascinating suggestion that answers all these questions. He points out that Chazal emphasize that there was a specific sin committed by the ancestors of the Jewish people that resulted directly in the Galus Mitzrayim and needed to be rectified before the Jewish people could end this Galus. That is the sin of Mechiras Yosef: One source is a Gemara in Shabbos that notes that because of Yaakov’s favoritism to Yosef, which led to Mechiras Yosef, the Jewish people had to be slaves in Mitzrayim. Since the Galus Mitzrayim began as a result of this sin, the Jewish people had to rectify it before they could leave. Hence, before the final Plague which would enable them to leave, they had to first do certain actions that would serve as a tikkun for the various aspects of the sin of selling Yosef.
The Chikrei Lev then goes through a number of details of the Korban Pesach where there is a clear parallel to details of Mechiras Yosef, but this time in reverse as the positive actions would serve as a rectification of the negative actions done back then.
The first most striking example is cited by Rabbeinu Bechaye. In the command to take a sheep for the Korban Pesach, the Torah uses the enigmatic word, mishchu. The meaning of this word is unclear and the commentaries offer a number of interpretations for it’s meaning. Rabbeinu Bechaye focuses on a different aspect of the word – he notes that it is the same word as used in Mechiras Yosef – ‘veyimshechu’ – for when the brothers pulled Yosef out of the pit. He says that this positive meshicha of the Mitzva serves in contrast to the negative meshicha of hundreds of years earlier.
Another parallel is that the people had to dip the agudas azov (bundle of hyssop) into blood. This corresponds to when the brothers dipped Yosef’s coat in blood to show that he had been killed. The Chikrei Lev continues that there is a very strong emphasis on the fact that the Korban Pesach should be eaten as a family, united. This serves to rectify the terrible split in the family of Yaakov Avinu. And finally, we can now answer why it was necessary to eat from the Korban before, not after the Tenth Plague. This served as a tikkun for the fact that the brothers calmly sat to eat after they had thrown Yosef into the pit. Measure for measure, to fix this eating that was done in a state of disunity, each family had to eat together in unity, to show that each family can be united.
The family nature of Pesach continues to this very day, with strong emphasis on the family getting together for the Seder and the fathers passing on the Mesora of Yetsias Mitzrayim to the children. Moreover, the emphasis on unity is not limited to the family – there is a special Minhag to give Kimcha d’pischa for our struggling brethren, and right at the beginning of the Seder we invite the needy to come and eat with us.
Sadly, we do not have the Korban Pesach at this time, but Pesach still reminds us of the importance of unity in the nation in general and in the family in particular. It is unfortunately all too common that family tensions can fester and ultimately lead to unpleasantness or worse. This can develop for many reasons, such as jealousy, or arrogance, but very often, disagreements over money are the cause. It is essential to consider that no matter how much money may be at stake, and how justified one may feel he is (normally both parties have the same level of self-justification), is it more important than keeping family unity? Fractures between families have numerous negative ramifications and on reflection, most people realize that far outweigh any monetary losses. The Mitzvos involved with the Korban Pesach remind us that we were only able to leave Mitzrayim when we could be unified as a nation and as families – may we all merit to internalize this lesson in our own lives.
 Chikrei Lev, Shemos, Parshas Bo, Maamar 9. Much of the basis of this Dvar Torah is from this Maamar.
 Shabbos, 10b.