The Rambam introduces the Mitzvah of reciting the Haggadah on Pesach in a most unusual manner.
"It is a positive Mitzvah of the Torah to tell of the miracles and the wonders which were done for our ancestors in Egypt on the night of the Fifteenth of Nissan, for it says, 'remember this day when you left Egypt' Shemot 13:3, just as it says, 'remember the Sabbath day.' Shemot 20:8. How do we know that it is the night of the fifteenth? The text states, 'and you shall tell your son on that day.' Shemot 13:8 . . . at the time when you have Matzah and Maror placed before you. Mishneh Torah, Chametz Umatzah, 7:1."
Normally in the Rabbinic tradition, the Mitzvah of Haggadah is based upon the verse, “and you shall tell your son.” Shemot 13:8. The Mishnah employs this verse at the crucial moment of the Haggadah where one is directed to think of himself as though he actually participated in the Exodus and beheld all the miracles which surrounded him. See Pesachim 116b. Indeed the Rambam himself used that verse in his Sefer Hamitzvot. In listing the positive commandments, he states,
"Telling of the Exodus from Egypt on the First Night of the Festival of Matzot: for it says, 'and you are tell your son on that day.' Sefer Hamitzvot, Positive Commandment 157."
In his listing of the Mitzvot, the Sefer Hachinuch under the heading: “The Telling of the Exodus from Egypt,” clearly states that the verse from which this Mitzvah is derived is “and you should tell your son” See Sefer Hachinuch, Mitzvah 21.
The Minchat Chinuch is concerned about the discrepancy between the Chinuch and the Rambam and attempts to reconcile the distinction between the two. He states that the two verses actually complete one another. If we just utilize the verse “remember the day” we might regard it as a daily requirement on the individual without the need to tell it to someone else even on the night of Pesach. If we use the verse, “you shall tell your son” we would apply it only to someone who has a son or someone else to which he could tell it. If one is alone, however, he would have no obligation to tell it at all. Thus we need both verses. See Minchat Chinuch on Mitzvah 21.
It is very difficult to understand the nature of this reconciliation because each author uses only one verse. Why does the Rambam avoid the conventional usage and use a verse that is not normally understood as the basis for the Mitzvah of Haggadah? And what is the point of supporting that verse with the commandment to remember the Sabbath? What is the real connection between remembering the Exodus and remembering the Sabbath?
In truth, however, there is one Rabbinic source where those two verses are used together and that is the Midrash Rabbah:
Rav Natan said, God said to Moshe . . .warn Israel, just as I created the world and said to them (Israel) to remember the Sabbath day as a remembrance of the act of creation, as it says, “Remember the Sabbath Day,” Likewise remember the miracles that I performed for you in Egypt and remember the day that you went out from there, for it says, “Remember this day that you went out of Egypt.” Midrash Rabbah, Shemot 19:7
Why is the Rambam the only authority which utilizes the Midrash in his major halakhic work, the Mishneh Torah, as the basis for his understanding of the Mitzvah of Haggadah? What is the power of the correlation of Haggadah and the Sabbath? Why is the verse “and you should tell your son” only used by the Rambam to identify the day and time of the Mitzvah of Haggadah rather than as the source of the Mitzvah?
In order to answer these questions, it is important to consider the following: In the Midrash, the verse dealing with remembering the Sabbath precedes the verse dealing with the Exodus. Thus, remembering the Sabbath is primary, while remembering the Exodus is secondary. In the Mishnah Torah, the opposite is the case. That of course is natural, because the topic at hand is the Exodus.
Nevertheless, the underlying significance and principle of remembering the Sabbath is what should be applied and understood with reference to remembering or discussing the Exodus. That principle is the concept of testimony or Eidut. The Mitzvah of Haggadah should be understood not simply as an act of telling the story of the Exodus, but should be regarded by the speaker as an act of testimony. One should regard himself as a witness bearing testimony.
This is similar to the act of Kiddush, the words we speak on the eve of the Sabbath, which are regarded by tradition as an act of testimony acknowledging that God is the creator of the universe. Thus we testify that God created the world in six days and rested on the seventh. And we also testify that God took us out of Egypt.
We see that many aspects of the Passover Seder were understood by our tradition as bearing witness to our redemption by God. For that reason, the Haggadah requires us to tell someone else about what he had personally witnessed. If one has no son, he tells his daughter, if he has no children he must tell his wife; if he is not married, he must tell someone else; and if he is all alone, he must tell himself as though he were two people. The words that he uses should be answers to specific questions. Thus we have the Four Questions and in addition, the Four Sons, each with a different question.
This is the basis of the requirement found in the Mishnah that one must view himself as though he himself had just left Egypt. This is reinforced by the Talmud where Rava States, that one also must say, “He took us out of there” Devarim 6:23, Pesachim 116b. Only one who personally experienced and was involved in the event could offer testimony as to what he saw and what had occurred.
Although it is true that there is a commandment to Remember the Exodus all the days of our life, Devarim 16:3 it is only on the night of Pesach that we have the structure of the Haggadah and that we have to tell it to someone else and not simply remember it ourselves.
Now we understand the difference between those two requirements On the night of Pesach we do not simply remember, but we become what we experienced. On the night of Pesach, the Talmud wants us to be so involved in the process of the Exodus, that we are able to transport ourselves to the very moment of that crucial event in our history. This is the underlying power and importance of the Haggadah.