Rabban Gamliel would say: Whoever does not discuss the following three things on Passover, has not fulfilled his obligation: the passover offering, matzah and maror.
The passover offering, which our ancestors ate during the time of the Holy Temple - for what reason did they do so? Because G‑d passed over their homes in Egypt, as it is written: "You shall say: It is a Passover-offering to the L‑rd, because He passed over the houses of the children of Israel in Egypt when He struck the Egyptians with a plague, and He saved our houses... "
This matzah that we eat - for what reason? Because the dough of our fathers did not have time to become leavened before the King of the kings of kings, the Holy One, blessed be He, revealed Himself to them and redeemed them. As it is written: "They baked matzah-cakes from the dough that they had brought out of Egypt, because it was not leavened; for they had been driven out of Egypt and could not delay, and they had also not prepared any provisions."
This maror (bitter herb) that we eat - for what reason? Because the Egyptians embittered our fathers' lives in Egypt, as it is written: "They made their lives bitter with hard work, with mortar and with bricks, and with all manner of work in the field; all their work which they made them serve with crushing labor."
From 1977 lecture by Rav Soloveitchik, transcribed by R. David Etengoff:
"The Rav was fond of the analytical and conceptual distinction between a nisa(object) and a nosa (subject). The former is something or someone acted upon, whereas the latter is an actor in the historical drama we call life. At first blush, we look at Pesach, Matzah, and Maror as mere objects that must be consumed during the Seder (i.e. inclusive of the Korban Pesach when the Holy Temple is extant). Yet, in a creative tour de force, Rav Soloveitchik perceived each of these items as a nosa, as an active participant in the mitzvah of Sippur Yitziat Mitzraim:
Sippur Yitziat Mitzraim is a blend of storytelling, Torah teaching, and eating symbolic food items. It is a fusion of the spoken word and the physiological functions of eating and drinking, the intermingling of physical pleasure with Torah debate, the combining of the word of G-d with an activity motivated by biological pressure and characteristic not only of man but of animals. Eating the paschal sacrifice, mazzah and maror constitutes a double mizvah. The mizvat akhilah, physically consuming these items, is per se, a religious performance, a maaseh kiyum mizvah. But eating the Pesach, mazzah, and maror is also the instrument or medium of Sippur Yitziat Mitzraim, telling the story of the Exodus. We narrate the story not only through speech but through eating as well. [Therefore,] in order to fulfill the mizvah of sippur in the most perfect manner, one must interpret and explicate the symbolic meaning of Pesach, mazzah, and maror."
Marbeh Lisaper, commentary on the Haggadah:
In every generation: All of this is part of Rabban Gamliel’s statement. It explains why matzah is considered a Torah law (d’oraita) while eating maror is rabbinic (d’rabbanan). Why is there a difference in the status of these two symbols? According to Rabban Gamliel we are obligated by the Torah to see ourselves as if we went forth from Egypt. The matzah serves as a reminder of this biblical mandate while maror reminds us of slavery (which we are not obligated by the Torah to remember.) Matzah allows us to see ourselves in this fashion.
Yet, what purpose is there in “seeing ourselves” as if we personally went forth from Egypt; many generations have passed since the Exodus - what good is there is in seeing the redemption in this way? This teaches us that the purpose of the redemption was not just the liberation from slavery in Egypt but also the fact that we could enter the land of Israel, build the temple, and seek atonement for our sins. Also the matzah alludes to the future redemption as well. The afikomen is an allusion to the final redemption, which is called tzafun bareikh, the hidden blessing. It is because of these hopes that scripture made matzah an obligation, “You shall eat matzot at night,” This is an allusion to the fact that we eat matzah during the night (of exile) which comes before the light (of redemption.)
