וַיַּרְעֵ֬ם בַּשָּׁמַ֨יִם ׀ יְֽהוָ֗ה וְ֭עֶלְיוֹן יִתֵּ֣ן קֹל֑וֹ בָּ֝רָ֗ד וְגַֽחֲלֵי־אֵֽשׁ׃
The LORD also thundered in the heavens, and the Most High gave forth His voice; hailstones and coals of fire.
Read kabbalistic (mystical) interpretation of Psalms 18:14: and classical mystical sources.