There were two stages to the liberation from Egypt: 1) The first night of Pesach. 2) The end of the interaction with what remained of Egypt, after the splitting of the sea. Why couldn’t it occur at one time? The gemara (Shabbat 118b) says that had Bnei Yisrael observed two Shabbatot, they would have been immediately liberated. This apparently refers to two types of Shabbatot: the standard one commemorating Creation; the holidays that Bnei Yisrael sanctified by their setting of the calendar. The Torah calls the first day of Pesach "Shabbat," so that the count of the omer begins the day after Shabbat (Vayikra 23:15). Why is this called a Shabbat, and why must Israel sanctify it? Almost everything is in Hashem’s hands, but man is charged with sanctifying the mundane. Man consists of contrasting elements. He is made from earth, but Hashem blew His Spirit into man’s nostrils. While the individual man struggles with internal contradictions, it is much more complex for a whole nation. While an individual can separate himself from the world of physical activity, an entire nation cannot. They must sew, harvest, etc. These take time and can "swallow up" the persona the person wants to be. When our forefathers were a family in Egypt, an individual could decide to have someone else take care of his physical needs. However, a nation needs to fulfill the goal of "I will bring you to the Land …" (Shemot 6:8). Even if, initially, they may have inherited riches from those they conquered (see Devarim 6:11), they had to start working the Land themselves. Hashem wanted them to be like all the nations, but also very different from other nations. They needed to learn to sing, but not of struggles, harvest, or first fruit. The experience of harvest needed to revolve around the rules of the Torah; the experience of the first fruit needed to be connected to the mitzva done at the Beit Hamikdash. Actions and times needed to be sanctified. These matters are related to the second Shabbat. Only Israel, as holy human beings, with spirits and bodies, can build this Shabbat; it cannot be divinely dictated. That is the reason that the harvest festival (Shavuot) is to be prepared for from the day after "man’s Shabbat." How do we create this Shabbat? It is by bringing a Korban Pesach, which is unique in that the main part of the Korban is eating rather than that which was put on the altar. Everyone, old and young, has to take the material meat and eat it in a manner of sanctification. This was a preparation for the full exodus, which had to be not just physical but also spiritual, so that something all new could emerge – a holy nation. Then one can start reaping the grain without it causing boastfulness; he can start preparing for the receiving of the Torah, to complete the liberation. Before the events at the sea, slavery was over but there was not a move from subjugation to liberation. We could have built an independent nation, but it might have looked like a Jewish Egypt, with all the technological and societal developments. Only after eating the Korban Pesach and appreciating the beauty of a holy, physical national life, Hashem could destroy Egypt in a manner that we would never see them again. Then, the people could sing – not just about the past, but for what it did for their future (yashir).
Beit Midrash Series Parashat Hashavua