מִן־הַשָּׁמַ֛יִם הִשְׁמִֽיעֲךָ֥ אֶת־קֹל֖וֹ לְיַסְּרֶ֑ךָּ וְעַל־הָאָ֗רֶץ הֶרְאֲךָ֙ אֶת־אִשּׁ֣וֹ הַגְּדוֹלָ֔ה וּדְבָרָ֥יו שָׁמַ֖עְתָּ מִתּ֥וֹךְ הָאֵֽשׁ׃
Out of heaven He made thee to hear His voice, that He might instruct thee; and upon earth He made thee to see His great fire; and thou didst hear His words out of the midst of the fire.
Read kabbalistic (mystical) interpretation of Deuteronomy 4:36: and classical mystical sources.