During the Seder, we recite Hallel (paragraphs from Psalms praising Hashem for salvation). However, our Sages split Hallel into two parts. The first part (Psa. 113:1-9; 114:1-8) is said after Sippur Yetziyas Mitzrayim (the telling of the story about our exodus from Egypt), before the meal. The second part (Psa. 115:1-11; 115:12-18; 116:1-11; 116:12-19; 117:1-2; 118:5-29) is recited after the meal.
Why is Hallel split into two? Why is it not recited all together as is the case during the rest of the year?
The Levushei Mordechai (Orach Chaim, chap. 480, cited in the Pri Megadim's Aishel Avraham chap. 486) says that the reason for this split is that the first part of Hallel focuses on the exodus from Egypt. Therefore, it is recited with the first part of the Haggadah which focuses on the exodus from Egypt. However, the second part of Hallel focuses on other redemptions from other exiles. Therefore it is recited with the second part of the Haggadah which focuses on other exiles and redemptions.
Although this does answer the question, it raises another. Why does the second part of the Haggadah focus on other exiles and redemptions? Passover celebrates the exodus from Egypt. Therefore, we should be focusing only on the exodus from Egypt. Why would we want to distract ourselves from the main theme of the evening?
Moreover, Rebbi Levi says that the four cups of wine that we drink during the Seder night represent the four kingdoms (Babylonian, Median, Greek, and Roman) which sent us into exile, which we were subsequently redeemed from (Yerushalmi, Pesachim, chap. 10, "Arvei Pesachim", Halachah Aleph). Again, why are we celebrating redemptions from other exiles when we are supposed to be focusing on the exodus from Egypt?
Another disturbing issue is that all of the Midrashim claim that the Jewish people went through only four exiles (Bavel, Madai, Yavan, and Edom; see for example Bereishis Rabba, 44:17). The question is what happened to the Egyptian Exile? That exile should certainly deserve a place amongst the exiles. After all, there is an entire holiday in which we celebrate our salvation from Egypt. It's called Passover. It was the first of the exiles. Our Sages should have mentioned that the Jews went through "five" exiles, not four.
The B'nei Yissaschar (Nissan, 4:2) shares a fundamental teaching which will address all of these questions. He says that the Egyptian Exile was the all-inclusive exile, incorporating the other four exiles. In other words, all the pain and suffering that the Jewish people experienced throughout the four exiles, was experienced by the Jews in Egypt simultaneously.
This is even hinted to in a verse about the Egyptian Exile that says, "And it came to pass during those "yamim harabim" (many days, etc....Ex. 2:23). The Hebrew word for "many" is "rabim." This word is spelled with four letters. They are: reish, beis, yud, and mem. These four letters serve as an acronym for "Romi" (the Roman Exile), "Bavel" (the Babylonian Exile), "Yavan" (the Greek Exile), and "Madai" (the Median Exile).
The Dorshei Reshumos and the Megaleh Amukos (Toldos, pg. 27a) say that this comes to teach us that the Jews spent "many" days suffering in Mitzrayim. Meaning, the many days in Mitzrayim included all the days of the other exiles as well.
The B'nei Yissaschar says that this teaching is very hopeful to us, because if we had the stuff that it takes to survive the Egyptian Exile, then we most certainty have the wherewithal to survive all of the future exiles. The reasoning is that if we had the capacity to endure all four exiles simultaneously, then we can most definitely last each of the other exiles individually, because each one is only a fourth of what we went through in Mitzrayim.
This is why we drink four cups of wine hinting at the four kingdoms. This is not a distraction from our focus on Egypt. Rather, it is an enhancement. Once we celebrate our exodus from Egypt, we realize that we can survive anything. Survival has been imprinted into our spiritual DNA. This is why we raise the cup of salvation to celebrate redemption from the other exiles, even if it has not yet come to fruition. This is because we know that it's in the bag. You can take it to the bank. It's just a matter of time, but we will be redeemed. Therefore we already drink the cup of thanks to Hashem for the redemption that we know for certainty is going to happen.
Based on this teaching of the B'nei Yissaschar, perhaps we could suggest that this is why all of the Midrashim refer to only four exiles, apparently dismissing the fifth Egyptian Exile. It is because our Sages are teaching us that there are only four exiles. It's just that once upon a time, those four exiles happened separately. However, once upon a time, those four exiles happened simultaneously. Egypt was not a fifth and separate exile. Rather, it was the combination of all four.
This also explains why our Sages split the Haggadah and hallel into two parts, focusing on other redemptions from other exiles in the second part, even though it seemingly has nothing to do with our exodus from Egypt. The answer is that it's got everything to do with our exodus from Egypt. Yetziyas Mitzrayim broke the ice and paved the way for there to be other redemptions. We praise Hashem for both on Passover night, even if the final redemption has not happened yet, because we know that it is going to happen. We may not know when or how, but we are certain that it will come to be. Since Yetziyas Mitzrayim caused the other salvations to transpire, it is very fitting to thank Hashem for them on Passover night.
Perhaps we could add that every single year, during the holiday of Passover, the energy of redemption is in the air. This means that we could also experience salvation on a personal level. When we go through financial difficulties, family problems or medical issues, they are our personal Mitzrayims. To the extent that we plug into the story about our exodus from Egypt, we can also experience redemption from our personal Mitzrayims. If Yetziyas Mitzrayim caused the salvation of our national exiles, then it can also generate salvation from our individual exiles.
So let's try to prepare for Pesach, not just by cleaning our homes, work places, and automobiles from leaven, but also by learning some more Torah about Passover that we will be able to share with relatives and friends at the Seder table. Let us also try to go as long as we can on Passover night discussing the story about our Exodus. If we plan on staying up all night on Shavuos in order to fulfill a custom, we should certainly intend on staying up all night of Leil Haseder which is a fulfillment of a Torah Mitzvah (Ex. 13:8).
Not only will we fulfill a Torah Mitzvah every moment of that night, but we will also be able to draw from the reservoir of redemption and experience salvation in our personal lives.
So, may we all be blessed with Torah filled Seders, in order to extract the energy of redemption and thus be rescued from personal and national bondage.