מִנֹּ֗גַהּ נֶ֫גְדּ֥וֹ עָבָ֥יו עָבְר֑וּ בָּ֝רָ֗ד וְגַֽחֲלֵי־אֵֽשׁ׃
At the brightness before Him, there passed through His thick clouds Hailstones and coals of fire.
Read kabbalistic (mystical) interpretation of Psalms 18:13: and classical mystical sources.