Exodus 9:23

The Lord sent thunder - קלת koloth , voices; but loud, repeated peals of thunder are meant.

And the fire ran along upon the ground - ארצה אש ותהלך vattihalac esh aretsah , and the fire walked upon the earth. It was not a sudden flash of lightning, but a devouring fire, walking through every part, destroying both animals and vegetables; and its progress was irresistible.