Another interpretation: "For your voice is sweet": "I will sing to the LORD" (Exodus 15:1); "And your appearance comely": at the sea, "From the mouth of infants and sucklings You have founded strength" (Psalms 8:3). "And they stationed themselves at the underside of the mountain": Rabbi Avdimi bar Chama bar Chasa said, this teaches that the Holy One, blessed be He, held the mountain over them like a barrel, and said to them: If you accept the Torah, well and good; and if not, there shall be your burial. Rav Acha bar Yaakov said: from here there is a great protest against the Torah [a claim that the covenant was made under coercion]. Rava said: even so, they accepted it again in the days of Ahasuerus, as it is written, "The Jews confirmed and accepted upon themselves" (Esther 9:27)—they confirmed what they had already accepted. Rabbi Shimon ben Lakish said: what is the meaning of what is written, "And it was evening and it was morning, the sixth day" (Genesis 1:31)? Why the extra letter heh [the definite article in 'the sixth']? It teaches that the Holy One, blessed be He, made a condition with the works of creation, and so on, as written above.
The Mountain Held Overhead and Accepted Again in Esthers Days
Yalkut Shimoni on Torah 283:2
דָּבָר אַחֵר כִּי "קוֹלֵךְ עָרֵב", "אָשִׁירָה לַה'", "וּמַרְאֵיךְ נָאוֶה", עַל הַיָּם, (תהלים ח, ג) "מִפִּי עוֹלְלִים וְיֹנְקִים יִסַּדְתָּ עֹז". וַיִּתְיַצְּבוּ בְּתַחְתִּית הָהָר, אָמַר רַבִּי אַבְדִימֵי בַּר חָמָא בַּר מַחְסַיָּא, מְלַמֵּד שֶׁכָּפָה הַקָּדוֹשׁ בָּרוּךְ הוּא עֲלֵיהֶם הַר כְּגִיגִית, אָמַר לָהֶם אִם אַתֶּם מְקַבְּלִים אֶת הַתּוֹרָה מוּטָב, וְאִם לָאו שָׁם תְּהֵא קְבוּרַתְכֶם. אָמַר רַב אָחָא בַּר יַעֲקֹב, מִכָּאן מוֹדָעָא רַבָּה לְאוֹרַיְיתָא, אָמַר רָבָא, אַף עַל פִּי כֵן הֲדַר קִבְּלוּהָ בִּימֵי אֲחַשְׁוֵרוֹשׁ דִּכְתִיב (אסתר ט, כז) "קִיְּמוּ וְקִבְּלֻ הַיְּהוּדִים", קִיְּמוּ מַה שֶׁקִּבְּלוּ כְּבָר. אָמַר רַבִּי שִׁמְעוֹן בֶּן לָקִישׁ, מַאי דִּכְתִיב (בראשית א, לא) "וַיְהִי עֵרֶב וַיְהִי בֹקֶר יוֹם הַשִּׁשִּׁי" הֵ"א יְתֵרָה לָמָּה לִי, מְלַמֵּד שֶׁהִתְנָה הַקָּדוֹשׁ בָּרוּךְ הוּא עִם מַעֲשֵׂה בְּרֵאשִׁית וְכוּ' כִּדְכָתוּב לְעֵיל.