Exodus 9:10-12

Darby Translation

¹⁰ And they took ashes of the furnace, and stood before Pharaoh; and Moses sprinkled it toward the heavens; and it became boils [with] blisters breaking out on man and on cattle.

¹¹ And the scribes could not stand before Moses because of the boils; for the boils were on the scribes, and on all the Egyptians.

¹² And Jehovah made Pharaoh's heart stubborn, and he did not hearken to them, as Jehovah had told Moses.