וְהִשְׁמִ֨יעַ יְהוָ֜ה אֶת־ה֣וֹד קוֹל֗וֹ וְנַ֤חַת זְרוֹעוֹ֙ יַרְאֶ֔ה בְּזַ֣עַף אַ֔ף וְלַ֖הַב אֵ֣שׁ אוֹכֵלָ֑ה נֶ֥פֶץ וָזֶ֖רֶם וְאֶ֥בֶן בָּרָֽד׃
And the LORD will cause His glorious voice to be heard, And will show the lighting down of His arm, With furious anger, and the flame of a devouring fire, With a bursting of clouds, and a storm of rain, and hailstones.
Rashi on Isaiah
and the laying down of His arm This is not an expression of resting but an expression of placing, posement in O.F. Comp. (Exod. 10:14) “And placed it (וַיָּנַח) throughout the entire boundary of Egypt.” The placing of His might He will show in a flame by which the armies of Sennacherib were burnt.
Ibn Ezra on Isaiah
And the Lord shall cause His glorious voice to be heard. The people will be frightened, as they are when they hear the thunder.49This remark of I. E. seems to have been intended for the next verse.
Rashi on Isaiah
bursting (נֶפֶץ) an expression of more intense breaking, (shattering).