How does Matzah help tell our story?

Why do we eat matzah on Pesach?

שִׁבְעַ֤ת יָמִים֙ מַצּ֣וֹת תֹּאכֵ֔לוּ אַ֚ךְ בַּיּ֣וֹם הָרִאשׁ֔וֹן תַּשְׁבִּ֥יתוּ שְּׂאֹ֖ר מִבָּתֵּיכֶ֑ם כִּ֣י ׀ כׇּל־אֹכֵ֣ל חָמֵ֗ץ וְנִכְרְתָ֞ה הַנֶּ֤פֶשׁ הַהִוא֙ מִיִּשְׂרָאֵ֔ל מִיּ֥וֹם הָרִאשֹׁ֖ן עַד־י֥וֹם הַשְּׁבִעִֽי׃
For seven days, matzot you are to eat;
already on the first day you are to get rid of leaven from your houses,
for anyone who eats what is fermented—from the first day until the seventh day—: that person shall be cut off from Israel!

But let's look at this mitzvah in context:

וַיֹּ֤אמֶר יְהֹוָה֙ אֶל־מֹשֶׁ֣ה וְאֶֽל־אַהֲרֹ֔ן בְּאֶ֥רֶץ מִצְרַ֖יִם לֵאמֹֽר׃ הַחֹ֧דֶשׁ הַזֶּ֛ה לָכֶ֖ם רֹ֣אשׁ חֳדָשִׁ֑ים רִאשׁ֥וֹן הוּא֙ לָכֶ֔ם לְחׇדְשֵׁ֖י הַשָּׁנָֽה׃ דַּבְּר֗וּ אֶֽל־כׇּל־עֲדַ֤ת יִשְׂרָאֵל֙ לֵאמֹ֔ר בֶּעָשֹׂ֖ר לַחֹ֣דֶשׁ הַזֶּ֑ה וְיִקְח֣וּ לָהֶ֗ם אִ֛ישׁ שֶׂ֥ה לְבֵית־אָבֹ֖ת שֶׂ֥ה לַבָּֽיִת׃ וְאִם־יִמְעַ֣ט הַבַּ֘יִת֮ מִהְי֣וֹת מִשֶּׂה֒ וְלָקַ֣ח ה֗וּא וּשְׁכֵנ֛וֹ הַקָּרֹ֥ב אֶל־בֵּית֖וֹ בְּמִכְסַ֣ת נְפָשֹׁ֑ת אִ֚ישׁ לְפִ֣י אׇכְל֔וֹ תָּכֹ֖סּוּ עַל־הַשֶּֽׂה׃ שֶׂ֥ה תָמִ֛ים זָכָ֥ר בֶּן־שָׁנָ֖ה יִהְיֶ֣ה לָכֶ֑ם מִן־הַכְּבָשִׂ֥ים וּמִן־הָעִזִּ֖ים תִּקָּֽחוּ׃ וְהָיָ֤ה לָכֶם֙ לְמִשְׁמֶ֔רֶת עַ֣ד אַרְבָּעָ֥ה עָשָׂ֛ר י֖וֹם לַחֹ֣דֶשׁ הַזֶּ֑ה וְשָׁחֲט֣וּ אֹת֗וֹ כֹּ֛ל קְהַ֥ל עֲדַֽת־יִשְׂרָאֵ֖ל בֵּ֥ין הָעַרְבָּֽיִם׃ וְלָֽקְחוּ֙ מִן־הַדָּ֔ם וְנָ֥תְנ֛וּ עַל־שְׁתֵּ֥י הַמְּזוּזֹ֖ת וְעַל־הַמַּשְׁק֑וֹף עַ֚ל הַבָּ֣תִּ֔ים אֲשֶׁר־יֹאכְל֥וּ אֹת֖וֹ בָּהֶֽם׃ וְאָכְל֥וּ אֶת־הַבָּשָׂ֖ר בַּלַּ֣יְלָה הַזֶּ֑ה צְלִי־אֵ֣שׁ וּמַצּ֔וֹת עַל־מְרֹרִ֖ים יֹאכְלֻֽהוּ׃ אַל־תֹּאכְל֤וּ מִמֶּ֙נּוּ֙ נָ֔א וּבָשֵׁ֥ל מְבֻשָּׁ֖ל בַּמָּ֑יִם כִּ֣י אִם־צְלִי־אֵ֔שׁ רֹאשׁ֥וֹ עַל־כְּרָעָ֖יו וְעַל־קִרְבּֽוֹ׃ וְלֹא־תוֹתִ֥ירוּ מִמֶּ֖נּוּ עַד־בֹּ֑קֶר וְהַנֹּתָ֥ר מִמֶּ֛נּוּ עַד־בֹּ֖קֶר בָּאֵ֥שׁ תִּשְׂרֹֽפוּ׃ וְכָ֘כָה֮ תֹּאכְל֣וּ אֹתוֹ֒ מׇתְנֵיכֶ֣ם חֲגֻרִ֔ים נַֽעֲלֵיכֶם֙ בְּרַגְלֵיכֶ֔ם וּמַקֶּלְכֶ֖ם בְּיֶדְכֶ֑ם וַאֲכַלְתֶּ֤ם אֹתוֹ֙ בְּחִפָּז֔וֹן פֶּ֥סַח ה֖וּא לַיהֹוָֽה׃ וְעָבַרְתִּ֣י בְאֶֽרֶץ־מִצְרַ֘יִם֮ בַּלַּ֣יְלָה הַזֶּה֒ וְהִכֵּיתִ֤י כׇל־בְּכוֹר֙ בְּאֶ֣רֶץ מִצְרַ֔יִם מֵאָדָ֖ם וְעַד־בְּהֵמָ֑ה וּבְכׇל־אֱלֹהֵ֥י מִצְרַ֛יִם אֶֽעֱשֶׂ֥ה שְׁפָטִ֖ים אֲנִ֥י יְהֹוָֽה׃ וְהָיָה֩ הַדָּ֨ם לָכֶ֜ם לְאֹ֗ת עַ֤ל הַבָּתִּים֙ אֲשֶׁ֣ר אַתֶּ֣ם שָׁ֔ם וְרָאִ֙יתִי֙ אֶת־הַדָּ֔ם וּפָסַחְתִּ֖י עֲלֵכֶ֑ם וְלֹֽא־יִֽהְיֶ֨ה בָכֶ֥ם נֶ֙גֶף֙ לְמַשְׁחִ֔ית בְּהַכֹּתִ֖י בְּאֶ֥רֶץ מִצְרָֽיִם׃ וְהָיָה֩ הַיּ֨וֹם הַזֶּ֤ה לָכֶם֙ לְזִכָּר֔וֹן וְחַגֹּתֶ֥ם אֹת֖וֹ חַ֣ג לַֽיהֹוָ֑ה לְדֹרֹ֣תֵיכֶ֔ם חֻקַּ֥ת עוֹלָ֖ם תְּחׇגֻּֽהוּ׃ שִׁבְעַ֤ת יָמִים֙ מַצּ֣וֹת תֹּאכֵ֔לוּ אַ֚ךְ בַּיּ֣וֹם הָרִאשׁ֔וֹן תַּשְׁבִּ֥יתוּ שְּׂאֹ֖ר מִבָּתֵּיכֶ֑ם כִּ֣י ׀ כׇּל־אֹכֵ֣ל חָמֵ֗ץ וְנִכְרְתָ֞ה הַנֶּ֤פֶשׁ הַהִוא֙ מִיִּשְׂרָאֵ֔ל מִיּ֥וֹם הָרִאשֹׁ֖ן עַד־י֥וֹם הַשְּׁבִעִֽי׃ וּבַיּ֤וֹם הָרִאשׁוֹן֙ מִקְרָא־קֹ֔דֶשׁ וּבַיּוֹם֙ הַשְּׁבִיעִ֔י מִקְרָא־קֹ֖דֶשׁ יִהְיֶ֣ה לָכֶ֑ם כׇּל־מְלָאכָה֙ לֹא־יֵעָשֶׂ֣ה בָהֶ֔ם אַ֚ךְ אֲשֶׁ֣ר יֵאָכֵ֣ל לְכׇל־נֶ֔פֶשׁ ה֥וּא לְבַדּ֖וֹ יֵעָשֶׂ֥ה לָכֶֽם׃ וּשְׁמַרְתֶּם֮ אֶת־הַמַּצּוֹת֒ כִּ֗י בְּעֶ֙צֶם֙ הַיּ֣וֹם הַזֶּ֔ה הוֹצֵ֥אתִי אֶת־צִבְאוֹתֵיכֶ֖ם מֵאֶ֣רֶץ מִצְרָ֑יִם וּשְׁמַרְתֶּ֞ם אֶת־הַיּ֥וֹם הַזֶּ֛ה לְדֹרֹתֵיכֶ֖ם חֻקַּ֥ת עוֹלָֽם׃ בָּרִאשֹׁ֡ן בְּאַרְבָּעָה֩ עָשָׂ֨ר י֤וֹם לַחֹ֙דֶשׁ֙ בָּעֶ֔רֶב תֹּאכְל֖וּ מַצֹּ֑ת עַ֠ד י֣וֹם הָאֶחָ֧ד וְעֶשְׂרִ֛ים לַחֹ֖דֶשׁ בָּעָֽרֶב׃ שִׁבְעַ֣ת יָמִ֔ים שְׂאֹ֕ר לֹ֥א יִמָּצֵ֖א בְּבָתֵּיכֶ֑ם כִּ֣י ׀ כׇּל־אֹכֵ֣ל מַחְמֶ֗צֶת וְנִכְרְתָ֞ה הַנֶּ֤פֶשׁ הַהִוא֙ מֵעֲדַ֣ת יִשְׂרָאֵ֔ל בַּגֵּ֖ר וּבְאֶזְרַ֥ח הָאָֽרֶץ׃ כׇּל־מַחְמֶ֖צֶת לֹ֣א תֹאכֵ֑לוּ בְּכֹל֙ מוֹשְׁבֹ֣תֵיכֶ֔ם תֹּאכְל֖וּ מַצּֽוֹת׃ {פ}
YHWH said to Moshe and to Aharon in the land of Egypt, saying: Let this month be for you the beginning of months,
the beginning-one let it be for you of the months of the year. Speak to the entire community of Israel, saying:
On the tenth day of this month
they are to take them, each-man, a lamb, according to their Fathers’ House, a lamb per household. Now if there be too few in the house for a lamb,
he is to take [it], he and his neighbor who is near his house, by the computation according to the [number of] persons;
each-man according to what he can eat you are to compute for the lamb. A wholly-sound male, year-old lamb shall be yours; from the sheep and from the goats are you to take it. It shall be for you in safekeeping, until the fourteenth day of this month,
and they are to slaughter it—the entire assembly of the community of Israel—between the setting-times. They are to take some of the blood and put it onto the two posts and onto the lintel,
onto the houses in which they eat it. And they are to eat the flesh on that night, roasted in fire,
and matzot;
with bitter-herbs they are to eat it. Do not eat any of it raw, or boiled, boiled in water,
but rather roasted in fire, its head along with its legs, along with its innards. You are not to leave any of it until morning;
what is left of it until morning, with fire you are to burn. And thus you are to eat it:
your hips girded, your sandals on your feet, and your sticks in your hand.
And you are to eat it in trepidation—
it is a Passover-Meal to YHWH. I will proceed through the land of Egypt on this night
and will strike down every firstborn in the land of Egypt, from man to beast,
while on all the gods of Egypt I will render judgment,
I, YHWH!. Now the blood will be a sign for you upon the houses where you are:
I will see the blood, and I will pass over you,
so that the blow will not become a bringer-of-ruin to you, when I strike down the land of Egypt. Now this day shall be a reminder for you;
you are to celebrate it as a pilgrimage-celebration for YHWH;
throughout your generations, as a law for the ages you are to celebrate it! For seven days, matzot you are to eat;
already on the first day you are to get rid of leaven from your houses,
for anyone who eats what is fermented—from the first day until the seventh day—: that person shall be cut off from Israel! And on the first day, a proclamation of holiness,
and on the seventh day, a proclamation of holiness shall there be for you—;
no kind of work is to be made on them;
only what belongs to every person to eat, that alone may be made-ready by you. And keep the [Festival of] matzot!
For on this same day
I have brought out your forces from the land of Egypt.
Keep this day throughout your generations as a law for the ages. In the first [month], on the fourteenth day of the month, at sunset, you are to eat matzot,
until the twenty-first day of the month, at sunset. For seven days, no leaven is to be found in your houses,
for whoever eats what ferments, that person shall be cut off from the community of Israel,
whether sojourner or native of the land. Anything that ferments you are not to eat;
in all your settlements, you are to eat matzot.

B'nei Yisrael are commanded to eat matzot before they even leave Egypt. There is no mention of them eating matzot because there wasn't time for the bread to rise.

The Torah describes other times to also eat matzot:

וַ֠יָּבֹ֠אוּ שְׁנֵ֨י הַמַּלְאָכִ֤ים סְדֹ֙מָה֙ בָּעֶ֔רֶב וְל֖וֹט יֹשֵׁ֣ב בְּשַֽׁעַר־סְדֹ֑ם וַיַּרְא־לוֹט֙ וַיָּ֣קׇם לִקְרָאתָ֔ם וַיִּשְׁתַּ֥חוּ אַפַּ֖יִם אָֽרְצָה׃ וַיֹּ֜אמֶר הִנֶּ֣ה נָּא־אֲדֹנַ֗י ס֣וּרוּ נָ֠א אֶל־בֵּ֨ית עַבְדְּכֶ֤ם וְלִ֙ינוּ֙ וְרַחֲצ֣וּ רַגְלֵיכֶ֔ם וְהִשְׁכַּמְתֶּ֖ם וַהֲלַכְתֶּ֣ם לְדַרְכְּכֶ֑ם וַיֹּאמְר֣וּ לֹּ֔א כִּ֥י בָרְח֖וֹב נָלִֽין׃ וַיִּפְצַר־בָּ֣ם מְאֹ֔ד וַיָּסֻ֣רוּ אֵלָ֔יו וַיָּבֹ֖אוּ אֶל־בֵּית֑וֹ וַיַּ֤עַשׂ לָהֶם֙ מִשְׁתֶּ֔ה וּמַצּ֥וֹת אָפָ֖ה וַיֹּאכֵֽלוּ׃

The two messengers came to Sedom at sunset,
as Lot was sitting at the gate of Sedom.
Lot saw them, arose to meet them and bowed low, nostrils to the earth. and said:
Now pray, my lords,
pray turn aside to your servant’s house,
spend the night, wash your feet;
[starting-early] you may go on your way.
They said:
No, rather we will spend the night in the square. But he pressed them exceedingly hard,
so they turned in to him and came into his house.
He made them a drinkfest and baked flat-cakes, and they ate.

וְזֹ֥את תּוֹרַ֖ת הַמִּנְחָ֑ה הַקְרֵ֨ב אֹתָ֤הּ בְּנֵֽי־אַהֲרֹן֙ לִפְנֵ֣י יְהֹוָ֔ה אֶל־פְּנֵ֖י הַמִּזְבֵּֽחַ׃ וְהֵרִ֨ים מִמֶּ֜נּוּ בְּקֻמְצ֗וֹ מִסֹּ֤לֶת הַמִּנְחָה֙ וּמִשַּׁמְנָ֔הּ וְאֵת֙ כׇּל־הַלְּבֹנָ֔ה אֲשֶׁ֖ר עַל־הַמִּנְחָ֑ה וְהִקְטִ֣יר הַמִּזְבֵּ֗חַ רֵ֧יחַ נִיחֹ֛חַ אַזְכָּרָתָ֖הּ לַיהֹוָֽה׃ וְהַנּוֹתֶ֣רֶת מִמֶּ֔נָּה יֹאכְל֖וּ אַהֲרֹ֣ן וּבָנָ֑יו מַצּ֤וֹת תֵּֽאָכֵל֙ בְּמָק֣וֹם קָדֹ֔שׁ בַּחֲצַ֥ר אֹֽהֶל־מוֹעֵ֖ד יֹאכְלֽוּהָ׃ לֹ֤א תֵאָפֶה֙ חָמֵ֔ץ חֶלְקָ֛ם נָתַ֥תִּי אֹתָ֖הּ מֵאִשָּׁ֑י קֹ֤דֶשׁ קׇֽדָשִׁים֙ הִ֔וא כַּחַטָּ֖את וְכָאָשָֽׁם׃ כׇּל־זָכָ֞ר בִּבְנֵ֤י אַהֲרֹן֙ יֹֽאכְלֶ֔נָּה חׇק־עוֹלָם֙ לְדֹרֹ֣תֵיכֶ֔ם מֵאִשֵּׁ֖י יְהֹוָ֑ה כֹּ֛ל אֲשֶׁר־יִגַּ֥ע בָּהֶ֖ם יִקְדָּֽשׁ׃ {פ}

Now this is the Instruction [regarding] the grain-gift:
Aharon’s sons must bring it near, before the presence of YHWH,
in front of the altar. There shall be set-aside from it, by the handful, some of the flour of the grain-gift and some of its oil, with all the frankincense that is on the grain-gift,
and it is to be turned into smoke on the altar, as a soothing savor, as its reminder-portion to YHWH. What is left of it, Aharon and his sons are to eat;
unleavened it is to be eaten, in a holy place,
in the courtyard of the Tent of Appointment they are to eat it. It is not to be baked with leaven;
as their portion I have given it from my fire-offerings
—it is a holiest holy-portion, like the hattat-offering and like the asham-offering. Any male among the Children of Aharon may eat it,
[as] an allotment for the ages, throughout your generations, from the fire-offerings of YHWH;
whatever touches it becomes holy [property].

But the idea that B'nei Yisrael ate matzah because the dough did not have time to rise also comes from Torah:

וַיֹּאפ֨וּ אֶת־הַבָּצֵ֜ק אֲשֶׁ֨ר הוֹצִ֧יאוּ מִמִּצְרַ֛יִם עֻגֹ֥ת מַצּ֖וֹת כִּ֣י לֹ֣א חָמֵ֑ץ כִּֽי־גֹרְשׁ֣וּ מִמִּצְרַ֗יִם וְלֹ֤א יָֽכְלוּ֙ לְהִתְמַהְמֵ֔הַּ וְגַם־צֵדָ֖ה לֹא־עָשׂ֥וּ לָהֶֽם׃

Now they baked the dough which they had brought out of Egypt into matzot cakes, for it had not fermented,
for they had been driven out of Egypt, and were not able to linger,
and neither had they made provisions for themselves.

And finds its way into the Haggadah:

רַבָּן גַּמְלִיאֵל הָיָה אוֹמֵר: כָּל שֶׁלֹּא אָמַר שְׁלשָׁה דְּבָרִים אֵלּוּ בַּפֶּסַח, לא יָצָא יְדֵי חוֹבָתוֹ, וְאֵלּוּ הֵן: פֶּסַח, מַצָּה, וּמָרוֹר.

מַצָּה זוֹ שֶׁאָנוֹ אוֹכְלִים, עַל שׁוּם מַה? עַל שׁוּם שֶׁלֹּא הִסְפִּיק בְּצֵקָם שֶׁל אֲבוֹתֵינוּ לְהַחֲמִיץ עַד שֶׁנִּגְלָה עֲלֵיהֶם מֶלֶךְ מַלְכֵי הַמְּלָכִים, הַקָּדוֹשׁ בָּרוּךְ הוּא, וּגְאָלָם, שֶׁנֶּאֱמַר: וַיֹּאפוּ אֶת-הַבָּצֵק אֲשֶׁר הוֹצִיאוּ מִמִּצְרַיִם עֻגֹת מַצּוֹּת, כִּי לֹא חָמֵץ, כִּי גֹרְשׁוּ מִמִּצְרַיִם וְלֹא יָכְלוּ לְהִתְמַהְמֵהַּ, וְגַם צֵדָה לֹא עָשׂוּ לָהֶם.

Rabban Gamliel was accustomed to say, Anyone who has not said these three things on Pesach has not fulfilled his obligation, and these are them: the Pesach sacrifice, matsa and marror...

This matzah that we are eating, for the sake of what [is it]? For the sake [to commemorate] that our ancestors' dough was not yet able to rise, before the King of the kings of kings, the Holy One, blessed be He, revealed [Himself] to them and redeemed them, as it is stated (Exodus 12:39); "And they baked the dough which they brought out of Egypt into matzah cakes, since it did not rise; because they were expelled from Egypt, and could not tarry, neither had they made for themselves provisions."

We begin the seder with a completely different definition of matzah:

הָא לַחְמָא עַנְיָא דִּי אֲכָלוּ אַבְהָתָנָא בְאַרְעָא דְמִצְרָיִם. כָּל דִכְפִין יֵיתֵי וְיֵיכֹל, כָּל דִצְרִיךְ יֵיתֵי וְיִפְסַח. הָשַּׁתָּא הָכָא, לְשָׁנָה הַבָּאָה בְּאַרְעָא דְיִשְׂרָאֵל. הָשַּׁתָּא עַבְדֵי, לְשָׁנָה הַבָּאָה בְּנֵי חוֹרִין.

This is the bread of affliction/poverty that our ancestors ate in the land of Egypt. Anyone who is famished should come and eat, anyone who is in need should come and partake of the Pesach sacrifice. Now we are here, next year we will be in the land of Israel; this year we are slaves, next year we will be free people.

Kimcha Davshuna by Rabbi Yochanan ben Yosef Treves (16th century Italy)

Ha lachma anya: Our ancestors ate bread like this in Egypt. Did our ancestors eat matzah in Egypt? Doesn’t scripture state, "And they baked unleavened cakes of the dough that they had taken out of Egypt for it was not leavened since they were driven out of Egypt and could not delay; nor had they prepared provisions for themselves." (Exodus 12:39) So they did not have unleavened bread until after they left Egypt, Isaac Abarbanel explains in his commentary, that when the Israelites were enslaved in Egypt toiling with hard labor, the Egyptians gave them matzah to eat which was hard to digest, just as employers often give their employees food that will not be digested quickly today.

Kos Eliyahu by Rabbi Eliyahu Ben Harush (19th century Morocco)

Ha lachma anya... Why did the Israelites eat matzah before they left Egypt? It was a portent of what was to come for the Israelites. It was a sign that they would leave Egypt in such haste that they would not have time to bake bread or for their dough to rise. Abudraham offers this explanation later when commenting on the passage in the Haggadah, “This matzah, for what reason?”

Divrei Negidim by Rabbi Yehudah Yudel Rosenberg (20th century Poland)

Matzah and Simplicity There is another way in which matzah is related to the bread of poverty, and redemption. The poor person has nothing, so his life is simplified and he stands detached from the world of things. In this complex material world such simplicity is considered a shortcoming. In the divine realm (olam hapashut), simplicity is a virtue. That is why we are commanded to eat matzah, the simplest form of bread. It contains nothing but the most essential ingredients… Israel was redeemed on this night from the complex material world through the higher spiritual realm. So, too, we are commanded to eat matzah which epitomizes this simplicity of the divine realm.

What else might the matzah represent?

וּשְׁמַרְתֶּם֮ אֶת־הַמַּצּוֹת֒ כִּ֗י בְּעֶ֙צֶם֙ הַיּ֣וֹם הַזֶּ֔ה הוֹצֵ֥אתִי אֶת־צִבְאוֹתֵיכֶ֖ם מֵאֶ֣רֶץ מִצְרָ֑יִם וּשְׁמַרְתֶּ֞ם אֶת־הַיּ֥וֹם הַזֶּ֛ה לְדֹרֹתֵיכֶ֖ם חֻקַּ֥ת עוֹלָֽם׃
And keep the [Festival of] matzot!
For on this same day
I have brought out your forces from the land of Egypt.
Keep this day throughout your generations as a law for the ages.

Commentary by Rabbi Shlomo Yitzchaki, also known as Rashi (11th century France)

(א) ושמרתם את המצות. שלא יבאו לידי חמוץ מכאן אמרו תפח, תלטוש בצונן רבי יאשיה אומר אל תהי קורא את המצות אלא את המצוות, כדרך שאין מחמיצין את המצה כך אין מחמיצין את המצוה אלא אם באה לידך עשה אותה מיד:

You must be vigilant regarding the matzos. So that they not come to be leavened… Rabbi Yoshiah said do not read it as "matzos", but rather as "mitzvahs". Just as we do not allow the matzah to leaven, so we do not allow a mitzvah to leaven. Rather, if the opportunity comes to you, do it immediately.

וַיֹּ֨אמֶר מֹשֶׁ֜ה אֶל־הָעָ֗ם זָכ֞וֹר אֶת־הַיּ֤וֹם הַזֶּה֙ אֲשֶׁ֨ר יְצָאתֶ֤ם מִמִּצְרַ֙יִם֙ מִבֵּ֣ית עֲבָדִ֔ים כִּ֚י בְּחֹ֣זֶק יָ֔ד הוֹצִ֧יא יְהֹוָ֛ה אֶתְכֶ֖ם מִזֶּ֑ה וְלֹ֥א יֵאָכֵ֖ל חָמֵֽץ׃
Moshe said to the people:
Remember this day in mind,
on which you went out from Egypt, from a house of serfs,
for by strength of hand YHWH brought you out from here:
no fermentation is to be eaten.

Haamek Davar by Naphtali Zevi Yehudah Berlin, also known as the Netziv (19th century Belarus)

ולא יאכל חמץ. כדי להשריש הזכירה בלב על ידי איזה פעולה המראה ומזכיר זה הענין צויתי שלא יאכל חמץ. דמצה אין בה יתרון על ידי תחבולות ידי האדם להעלות העיסה יותר מהקמח והמים שנבראים ממנו יתברך.

You shall not eat chametz. I commanded you not to eat chametz in order to root the awareness of this idea in the heart through some action that teaches and reminds us. Matzah does not benefit from the stratagems of human hands, to rise the dough any more than bread and water- which were created by the Blessed One.

Matzah is also used at other moments when we encounter the Divine.

וְזֹ֥את תּוֹרַ֖ת זֶ֣בַח הַשְּׁלָמִ֑ים אֲשֶׁ֥ר יַקְרִ֖יב לַיהֹוָֽה׃ אִ֣ם עַל־תּוֹדָה֮ יַקְרִיבֶ֒נּוּ֒ וְהִקְרִ֣יב ׀ עַל־זֶ֣בַח הַתּוֹדָ֗ה חַלּ֤וֹת מַצּוֹת֙ בְּלוּלֹ֣ת בַּשֶּׁ֔מֶן וּרְקִיקֵ֥י מַצּ֖וֹת מְשֻׁחִ֣ים בַּשָּׁ֑מֶן וְסֹ֣לֶת מֻרְבֶּ֔כֶת חַלֹּ֖ת בְּלוּלֹ֥ת בַּשָּֽׁמֶן׃ עַל־חַלֹּת֙ לֶ֣חֶם חָמֵ֔ץ יַקְרִ֖יב קׇרְבָּנ֑וֹ עַל־זֶ֖בַח תּוֹדַ֥ת שְׁלָמָֽיו׃
Now this is the Instruction [regarding] the sacrifice of shalom that is brought-near for YHWH: if [it is] on account of thanksgiving that he brings-it-near,
he is to bring-near along with the sacrifice of thanksgiving:
matza cakes, mixed with oil, matza wafers smeared with oil,
and flour well-stirred into cakes, mixed with oil. Along with cakes of leavened bread he is to bring-near his near-offering,
along with his thanksgiving sacrifice of shalom.
וַיֹּ֤אמֶר יְהוָה֙ אֶל־יְהוֹשֻׁ֔עַ הַיּ֗וֹם גַּלּ֛וֹתִי אֶת־חֶרְפַּ֥ת מִצְרַ֖יִם מֵעֲלֵיכֶ֑ם וַיִּקְרָ֞א שֵׁ֣ם הַמָּק֤וֹם הַהוּא֙ גִּלְגָּ֔ל עַ֖ד הַיּ֥וֹם הַזֶּֽה׃ וַיַּחֲנ֥וּ בְנֵֽי־יִשְׂרָאֵ֖ל בַּגִּלְגָּ֑ל וַיַּעֲשׂ֣וּ אֶת־הַפֶּ֡סַח בְּאַרְבָּעָה֩ עָשָׂ֨ר י֥וֹם לַחֹ֛דֶשׁ בָּעֶ֖רֶב בְּעַֽרְב֥וֹת יְרִיחֽוֹ׃ וַיֹּ֨אכְל֜וּ מֵעֲב֥וּר הָאָ֛רֶץ מִמָּֽחֳרַ֥ת הַפֶּ֖סַח מַצּ֣וֹת וְקָל֑וּי בְּעֶ֖צֶם הַיּ֥וֹם הַזֶּֽה׃ וַיִּשְׁבֹּ֨ת הַמָּ֜ן מִֽמָּחֳרָ֗ת בְּאָכְלָם֙ מֵעֲב֣וּר הָאָ֔רֶץ וְלֹא־הָ֥יָה ע֛וֹד לִבְנֵ֥י יִשְׂרָאֵ֖ל מָ֑ן וַיֹּאכְל֗וּ מִתְּבוּאַת֙ אֶ֣רֶץ כְּנַ֔עַן בַּשָּׁנָ֖ה הַהִֽיא׃ (ס)
And the LORD said to Joshua, “Today I have rolled away from you the disgrace of Egypt.” So that place was called Gilgal, as it still is. Encamped at Gilgal, in the steppes of Jericho, the Israelites offered the passover sacrifice on the fourteenth day of the month, toward evening. On the day after the passover offering, on that very day, they ate of the produce of the country, unleavened bread and parched grain. On that same day, when they ate of the produce of the land, the manna ceased. The Israelites got no more manna; that year they ate of the yield of the land of Canaan.
וַיֹּ֤אמֶר אֵלָיו֙ יְהוָ֔ה כִּ֥י אֶהְיֶ֖ה עִמָּ֑ךְ וְהִכִּיתָ֥ אֶת־מִדְיָ֖ן כְּאִ֥ישׁ אֶחָֽד׃ וַיֹּ֣אמֶר אֵלָ֔יו אִם־נָ֛א מָצָ֥אתִי חֵ֖ן בְּעֵינֶ֑יךָ וְעָשִׂ֤יתָ לִּי֙ א֔וֹת שָׁאַתָּ֖ה מְדַבֵּ֥ר עִמִּֽי׃ אַל־נָ֨א תָמֻ֤שׁ מִזֶּה֙ עַד־בֹּאִ֣י אֵלֶ֔יךָ וְהֹֽצֵאתִי֙ אֶת־מִנְחָתִ֔י וְהִנַּחְתִּ֖י לְפָנֶ֑יךָ וַיֹּאמַ֕ר אָנֹכִ֥י אֵשֵׁ֖ב עַ֥ד שׁוּבֶֽךָ׃ וְגִדְע֣וֹן בָּ֗א וַיַּ֤עַשׂ גְּדִֽי־עִזִּים֙ וְאֵיפַת־קֶ֣מַח מַצּ֔וֹת הַבָּשָׂר֙ שָׂ֣ם בַּסַּ֔ל וְהַמָּרַ֖ק שָׂ֣ם בַּפָּר֑וּר וַיּוֹצֵ֥א אֵלָ֛יו אֶל־תַּ֥חַת הָאֵלָ֖ה וַיַּגַּֽשׁ׃ (ס) וַיֹּ֨אמֶר אֵלָ֜יו מַלְאַ֣ךְ הָאֱלֹהִ֗ים קַ֣ח אֶת־הַבָּשָׂ֤ר וְאֶת־הַמַּצּוֹת֙ וְהַנַּח֙ אֶל־הַסֶּ֣לַע הַלָּ֔ז וְאֶת־הַמָּרַ֖ק שְׁפ֑וֹךְ וַיַּ֖עַשׂ כֵּֽן׃
The LORD replied, “I will be with you, and you shall defeat Midian to a man.” And he said to Him, “If I have gained Your favor, give me a sign that it is You who are speaking to me: do not leave this place until I come back to You and bring out my offering and place it before You.” And He answered, “I will stay until you return.” So Gideon went in and prepared a kid, and [baked] unleavened bread from an ephah of flour. He put the meat in a basket and poured the broth into a pot, and he brought them out to Him under the terebinth. As he presented them, the angel of God said to him, “Take the meat and the unleavened bread, put them on yonder rock, and spill out the broth.” He did so.