"And the whole earth was of one language" (Genesis 11:1). They brought forth from their mouths and said: Once every one thousand six hundred fifty-six years this firmament totters; so come, let us make supports for it, one from the north and one from the south and one from the west, and this one here will support it from the east. "And one set of words" [u-devarim achadim]: words that were sharp [achudim]. The deed of the generation of the flood was made explicit; the deed of the generation of the dispersion was not made explicit. And they spoke words against the two "ones": against "Abraham was one" and against "the LORD our God, the LORD is One" (Deuteronomy 6:4). They said: It is not for Him to choose for Himself the upper realms and give us the lower ones; rather, come, let us make ourselves a tower and place an idol at its top and put a sword in its hand, and it will appear as though it is making war against Him.
The Builders Claimed the Sky Itself Was Collapsing
Yalkut Shimoni on Torah 62:6
(בראשית יא א) וַיְהִי כָל הָאָרֶץ שָׂפָה אֶחָת. הוֹצִיאוּ מִפִּיהֶם וְאָמְרוּ אֶחָד לְאֶלֶף וְשֵׁשׁ מֵאוֹת וַחֲמִשִּׁים וְשֵׁשׁ [שָׁנִים] הָרָקִיעַ הַזֶּה מִתְמוֹטֵט אֶלָּא בּוֹאוּ וְנַעֲשֶׂה לוֹ סְמוּכוֹת אֶחָד מִן הַצָּפוֹן וְאֶחָד מִן הַדָּרוֹם וְאֶחָד מִן הַמַּעֲרָב וְזֶה שֶׁכָּאן סְמָכוֹ מִן הַמִּזְרָח. וּדְבָרִים אֲחָדִים. דְּבָרִים אֲחוּדִים מַעֲשֵׂה דּוֹר הַמַּבּוּל נִתְפָּרֵשׁ מַעֲשֵׂה דּוֹר הַפְּלָגָה לֹא נִתְפָּרֵשׁ, וְאָמְרוּ דְּבָרִים עַל שְׁנֵי אֲחָדִים, עַל "אֶחָד הָיָה אַבְרָהָם" וְעַל (דברים ו, ד) "ה' אֱלֹהֵינוּ ה' אֶחָד". אָמְרוּ, לֹא כָּל הֵימֶנּוּ לָבוּר לוֹ אֶת הָעֶלְיוֹנִים וְלִתֵּן לָנוּ אֶת הַתַּחְתּוֹנִים, אֶלָּא בּוֹאוּ וְנַעֲשֶׂה לָנוּ מִגְדָּל וְנִתֵּן עֲבוֹדָה זָרָה בְּרֹאשׁוֹ וְנִתֵּן חֶרֶב בְּיָדָהּ וּתְהֵא נִרְאֵית כְּאִלּוּ עוֹשָׂה עִמּוֹ מִלְחָמָה.