What's the Big Deal about Yitziat Mitzrayim? or Mitzvot and their Connection to the Exodus

Ramban, parshat Bo, Shmot 13:16

And now I will tell you a general rule about the meaning of many commandments. From the time when idolatry was in the world, from the days of Enosh, the opinions about faith started to blur. Some deny the fundamental principle and say that the world existed prior [to God's creation] and they reject God and say, "It is not Him." And some reject His knowledge of specifics, and say, "How can He know?", and "Does God have knowledge?" And some concede His knowledge but reject His oversight, and make man to be like the fish of the sea, that God not supervise them and for them there is no punishment or reward! They say, "The Lord has abandoned the Earth." And when God favors a specific group or individual and does a miracle for them by changing the practice of the world and its nature, the nullification of these opinions becomes clear to everyone. The amazing miracle teaches that there is a God in the world who created it, and knows, supervises, and is omnipotent. And when this miracle is first proclaimed by the mouth of a prophet, the truth of prophecy also becomes clear through it - that God speaks with man and reveals His secret to His servants the prophets, The veracity of the Torah is thus established.

And therefore the verse states about the wonders (Exodus 8:18), "so that you will know that I am the Lord in the midst of the Earth," to teach about [His] active supervision, that He did not leave it to chance as they believe. It states (Exodus 9:29), "so that you will know that to the Lord is the Earth," to teach about [His] innovation [of the Earth] - since they are His, as He created them from nothing. And it states (Exodus 9:14), "in order that you will know that there is none like Me in the whole Earth," To teach about His ability, that He is the Decider of everything, there is no one who can stop Him. As the Egyptians rejected or were in doubt about all of this. And so, the great signs and wonders were reliable witnesses about faith in the Creator and the entire Torah.

And since the Holy One, blessed be He, will not do a sign or miracle in every generation to rebutt each evildoer or heretic, He commanded us that we should always make a memorial and a sign to that which our eyes saw. And we should copy this for our children, and their children for their children, and their children until the last generation. And [the Torah] was very strict about this, such that the punishment for eating chametz and for not giving the Pesach sacrifice (Numbers 9:13) is "Karet" (being cut off) (Exodus 12:15). And He required of us that we write all that was shown to us through signs and wonders on our arms and between our eyes, and also to write them at the entrances to houses in mezuzot. And [it required] that we mention it with our mouths in the morning and in the evening, as the sages said (Berakhot 21a), "[The blessing that mentions the leaving of Egypt and begins,] 'true and solid' is [an obligation from] the Torah," from that which is written (Deuteronomy 16:3), "in order that you remember the day of your leaving the land of Egypt all the days of your life." And [required] that we make a Sukkah every year.

And so [too], there are many commandments in remembrance of leaving Egypt. And all of it is to be a testimony for us for all generations about the wonders, that they not be forgotten; and that there not be an opening for the heretic to speak and reject faith in God. As one who buys a mezuzah for one zuz and affixes it to his entrance and has intent for its matter, he has already conceded to [God's] creation of the Earth and to the knowledge of the Creator, His supervision, and prophecy. And [such a person] believes in all of the outlines of the Torah, besides conceding that the kindness of the Creator to those who do His will is very great - as He took us out from that very slavery to freedom and great honor, in the merit of their forefathers who desired to fear His name.

And therefore they said (Avot 2:1), "Be careful with a light commandment as with a weighty one," since they are all very desirable and beloved - as through them a person concedes to his God all the time. And the intention of all the commandments is that we believe in our God and concede to Him that He is our Creator. And that is the intention of provenance, as we have no other explanation for the first provenance - and the highest God desires only from the lower beings that man should know and concede to his God that He created him. And the intention of raising of the voice in prayer and of synagogues and the merit of communal prayer is that there be a place for people to gather and concede to God that He created them and causes them to exist, and to publicize this and to say in front of Him, "We are Your creatures." And this is the intention of what they said, may their memory be blessed (Yerushalmi Taanit 2:5), "And they called to God with strength"(Jonah 3:8) - from here you learn that prayer requires [an audible] voice; the brazen is victorious over the timid (See Arukh's entry on chatzaf).

And from the great public miracles, a person can [also] concede to hidden miracles, which are the foundation of the entire Torah. As a person does not have a share in the Torah of Moshe, our teacher, until we believe that the things and events we [encounter] are all miracles; [and] there is no nature or custom of the world with them, whether with regard to the many or to the individual. But rather, if one does the commandments, his reward will bring him success and if the transgresses them, his punishment will cut him off - everything is the decree of the Most High, as I have already mentioned (Ramban on Genesis 17:1, and Exodus 6:2). And hidden miracles performed for many become publicized when they come from the objectives of the Torah in [the form] of the blessings and the curses, as the verse stated (Deuteronomy 29:23-24), "All the nations will say, 'Why did the Lord do thus to this land?'[...] They will say, 'Because they forsook the covenant of the Lord, God of their fathers," such that it will be publicized to all of the nations that it is from the Lord, as their punishment. And regarding the fulfillment [of the commandments], it states (Deuteronomy 28:10), "And all of the peoples of the land will see that the name of the Lord is called upon you and they will fear from you.'" And I will explain this more with God's help.