Exodus
Exodus 19:16-19
Describes the morning of the giving of the Torah at Sinai — thunder, lightning, and the sound of the shofar, with the entire nation standing at the mountain. This is the foundational scene that Shavuot night commemorates.
וַיְהִי֩ בַיּ֨וֹם הַשְּׁלִישִׁ֜י בִּֽהְיֹ֣ת הַבֹּ֗קֶר וַיְהִי֩ קֹלֹ֨ת וּבְרָקִ֜ים וְעָנָ֤ן כָּבֵד֙ עַל־הָהָ֔ר וְקֹ֥ל שֹׁפָ֖ר חָזָ֣ק מְאֹ֑ד וַיֶּחֱרַ֥ד כׇּל־הָעָ֖ם אֲשֶׁ֥ר בַּֽמַּחֲנֶֽה׃ וַיּוֹצֵ֨א מֹשֶׁ֧ה אֶת־הָעָ֛ם לִקְרַ֥את הָֽאֱלֹהִ֖ים מִן־הַֽמַּחֲנֶ֑ה וַיִּֽתְיַצְּב֖וּ בְּתַחְתִּ֥ית הָהָֽר׃
On the third day, as morning dawned, there was thunder, and lightning, and a dense cloud upon the mountain, and a very loud blast of the horn; and all the people who were in the camp trembled. Moses led the people out of the camp toward God, and they took their places at the foot of the mountain.