(מב) בַּסֻּכֹּ֥ת תֵּשְׁב֖וּ שִׁבְעַ֣ת יָמִ֑ים כָּל־הָֽאֶזְרָח֙ בְּיִשְׂרָאֵ֔ל יֵשְׁב֖וּ בַּסֻּכֹּֽת׃ (מג) לְמַעַן֮ יֵדְע֣וּ דֹרֹֽתֵיכֶם֒ כִּ֣י בַסֻּכּ֗וֹת הוֹשַׁ֙בְתִּי֙ אֶת־בְּנֵ֣י יִשְׂרָאֵ֔ל בְּהוֹצִיאִ֥י אוֹתָ֖ם מֵאֶ֣רֶץ מִצְרָ֑יִם אֲנִ֖י יְהוָ֥ה אֱלֹהֵיכֶֽם׃
Rashbam, Vayikra 23:42-43
You are to do this at the time you gather in the produce of the earth and your houses are filled with all the good things the earth produces such a grain, grape, wine and oil (olives). This is to be done in order that you will remember” כי בסוכות הושבתי את בני ישראל, in the desert for a period of 40 years when they neither owned land nor found themselves in a cultivated part of the earth. Remembering all this you will have ample reason to be grateful to the One Who has provided you with all of your present wealth and comfort. You must not fall into the trap of thinking that all this success is due to your own efforts. We find a similar thought expressed in Deuteronomy 8,2-3 “you shall remember all the way which the Lord your G’d has led you for these last 40 years…and He fed you the manna, etc.” Why do I command you to do all this? For the Lord your G’d brings you to a good …and you will eat and be satisfied, etc. As a result your heart may become haughty and you will credit yourself with all this as your own achievement. (Deuteronomy 8 7-18) In order that this will not happen and to show that the Israelites G’d’s part in their success they will move out of their solid houses as a reminder to the time when they had not been blessed with any of these benefits which they enjoy ever since inheriting the land of their forefathers. They acknowledge that it is G’d Who provides the Jewish people with the ability and valor.
Piskei Teshuvos 631:2
....if rain cannot penetrate in an area of four Tefachim then that area is considered invalid Sechach for all purposes. Others[34] however rule that so long as there is a 7×7 area that allows penetration of rain the entire Sukkah is Kosher.
Shulchan Aruch 631:5
Allowing the stars to be seen: Initially the Sechach must be thin and light enough for the large stars to be visible through the Sechach at night. Bedieved even if the Sechach is as thick as the roof of a house to the point that no rays of sun penetrate the Sechach, the Sukkah is valid so long as rain is able to penetrate through the Sechach as will be explained next.
Allowing rain to penetrate: If the Sechach is thick to the point that even rain is unable to penetrate it is invalid
Is the Sukkah a symbol of weakness and impermanence, or is it a symbol of protection, strength, permanence, etc.?
מִזְמ֥וֹר לְדָוִ֑ד בְּ֝בָרְח֗וֹ מִפְּנֵ֤י ׀ אַבְשָׁל֬וֹם בְּנֽוֹ׃
A psalm of David when he fled from his son Absalom.
יְ֭הוָה מָֽה־רַבּ֣וּ צָרָ֑י רַ֝בִּ֗ים קָמִ֥ים עָלָֽי׃
O LORD, my foes are so many! Many are those who attack me;
רַבִּים֮ אֹמְרִ֪ים לְנַ֫פְשִׁ֥י אֵ֤ין יְֽשׁוּעָ֓תָה לּ֬וֹ בֵֽאלֹהִ֬ים סֶֽלָה׃
many say of me, “There is no deliverance for him through God.”Selah.
וְאַתָּ֣ה יְ֭הוָה מָגֵ֣ן בַּעֲדִ֑י כְּ֝בוֹדִ֗י וּמֵרִ֥ים רֹאשִֽׁי׃
But You, O LORD, are a shield about me, my glory, He who holds my head high.
ק֭וֹלִי אֶל־יְהוָ֣ה אֶקְרָ֑א וַיַּֽעֲנֵ֨נִי מֵהַ֖ר קָדְשׁ֣וֹ סֶֽלָה׃
I cry aloud to the LORD, and He answers me from His holy mountain. Selah.
אֲנִ֥י שָׁכַ֗בְתִּי וָֽאִ֫ישָׁ֥נָה הֱקִיצ֑וֹתִי כִּ֖י יְהוָ֣ה יִסְמְכֵֽנִי׃
I lie down and sleep and wake again, for the LORD sustains me.
לֹֽא־אִ֭ירָא מֵרִבְב֥וֹת עָ֑ם אֲשֶׁ֥ר סָ֝בִ֗יב שָׁ֣תוּ עָלָֽי׃
I have no fear of the myriad forces arrayed against me on every side.
וּמֹשֶׁ֗ה הָיָ֥ה רֹעֶ֛ה אֶת־צֹ֛אן יִתְר֥וֹ חֹתְנ֖וֹ כֹּהֵ֣ן מִדְיָ֑ן וַיִּנְהַ֤ג אֶת־הַצֹּאן֙ אַחַ֣ר הַמִּדְבָּ֔ר וַיָּבֹ֛א אֶל־הַ֥ר הָאֱלֹהִ֖ים חֹרֵֽבָה
(ד) וַיַּ֥רְא יְהוָ֖ה כִּ֣י סָ֣ר לִרְא֑וֹת וַיִּקְרָא֩ אֵלָ֨יו
אֱלֹהִ֜ים מִתּ֣וֹךְ הַסְּנֶ֗ה וַיֹּ֛אמֶר מֹשֶׁ֥ה מֹשֶׁ֖ה וַיֹּ֥אמֶר הִנֵּֽנִי׃ (ה) וַיֹּ֖אמֶר אַל־תִּקְרַ֣ב הֲלֹ֑ם שַׁל־נְעָלֶ֙יךָ֙ מֵעַ֣ל רַגְלֶ֔יךָ כִּ֣י הַמָּק֗וֹם אֲשֶׁ֤ר אַתָּה֙ עוֹמֵ֣ד עָלָ֔יו אַדְמַת־קֹ֖דֶשׁ הֽוּא׃ (ו) וַיֹּ֗אמֶר אָנֹכִי֙ אֱלֹהֵ֣י אָבִ֔יךָ אֱלֹהֵ֧י אַבְרָהָ֛ם אֱלֹהֵ֥י יִצְחָ֖ק וֵאלֹהֵ֣י יַעֲקֹ֑ב וַיַּסְתֵּ֤ר מֹשֶׁה֙ פָּנָ֔יו כִּ֣י יָרֵ֔א מֵהַבִּ֖יט אֶל־הָאֱלֹהִֽים׃ (ז) וַיֹּ֣אמֶר יְהוָ֔ה רָאֹ֥ה רָאִ֛יתִי אֶת־עֳנִ֥י עַמִּ֖י אֲשֶׁ֣ר בְּמִצְרָ֑יִם וְאֶת־צַעֲקָתָ֤ם שָׁמַ֙עְתִּי֙ מִפְּנֵ֣י נֹֽגְשָׂ֔יו כִּ֥י יָדַ֖עְתִּי אֶת־מַכְאֹבָֽיו׃ (ח) וָאֵרֵ֞ד לְהַצִּיל֣וֹ ׀ מִיַּ֣ד מִצְרַ֗יִם וּֽלְהַעֲלֹתוֹ֮ מִן־הָאָ֣רֶץ הַהִוא֒ אֶל־אֶ֤רֶץ טוֹבָה֙ וּרְחָבָ֔ה אֶל־אֶ֛רֶץ זָבַ֥ת חָלָ֖ב וּדְבָ֑שׁ אֶל־מְק֤וֹם הַֽכְּנַעֲנִי֙ וְהַ֣חִתִּ֔י וְהָֽאֱמֹרִי֙ וְהַפְּרִזִּ֔י וְהַחִוִּ֖י וְהַיְבוּסִֽי׃ (ט) וְעַתָּ֕ה הִנֵּ֛ה צַעֲקַ֥ת בְּנֵי־יִשְׂרָאֵ֖ל בָּ֣אָה אֵלָ֑י וְגַם־רָאִ֙יתִי֙ אֶת־הַלַּ֔חַץ אֲשֶׁ֥ר מִצְרַ֖יִם לֹחֲצִ֥ים אֹתָֽם׃ (י) וְעַתָּ֣ה לְכָ֔ה וְאֶֽשְׁלָחֲךָ֖ אֶל־פַּרְעֹ֑ה וְהוֹצֵ֛א אֶת־עַמִּ֥י בְנֵֽי־יִשְׂרָאֵ֖ל מִמִּצְרָֽיִם׃ (יא) וַיֹּ֤אמֶר מֹשֶׁה֙ אֶל־הָ֣אֱלֹהִ֔ים מִ֣י אָנֹ֔כִי כִּ֥י אֵלֵ֖ךְ אֶל־פַּרְעֹ֑ה וְכִ֥י אוֹצִ֛יא אֶת־בְּנֵ֥י יִשְׂרָאֵ֖ל מִמִּצְרָֽיִם׃ (יב) וַיֹּ֙אמֶר֙ כִּֽי־אֶֽהְיֶ֣ה עִמָּ֔ךְ וְזֶה־לְּךָ֣ הָא֔וֹת כִּ֥י אָנֹכִ֖י שְׁלַחְתִּ֑יךָ בְּהוֹצִֽיאֲךָ֤ אֶת־הָעָם֙ מִמִּצְרַ֔יִם תַּֽעַבְדוּן֙ אֶת־הָ֣אֱלֹהִ֔ים עַ֖ל הָהָ֥ר הַזֶּֽה׃
Now Moses, tending the flock of his father-in-law Jethro, the priest of Midian, drove the flock into the wilderness, and came to Horeb,
(4) When the LORD saw that he had turned aside to look, God called to him out of the bush: “Moses! Moses!” He answered, “Here I am.” (5) And He said, “Do not come closer. Remove your sandals from your feet, for the place on which you stand is holy ground. (6) I am,” He said, “the God of your father, the God of Abraham, the God of Isaac, and the God of Jacob.” And Moses hid his face, for he was afraid to look at God.