Exodus 9:10-12

Lexham English Bible

¹⁰ And they took the soot of the smelting furnace, and they stood before Pharaoh, and Moses sprinkled it toward the heavens, and it became skin sores sprouting blisters on humans and on animals. ¹¹ And the magicians were not able to stand before Moses because of the skin sores, for the skin sores were on the magicians and on all the Egyptians. ¹² And Yahweh hardened Pharaoh’s heart, and he did not listen to them, as Yahweh had spoken to Moses.