Exodus 9:9-12

⁹Then it will become fine dust over all the land of Egypt, and will turn into boils breaking out with sores on every person and animal through all the land of Egypt.” ¹⁰So they took soot from a kiln, and stood before Pharaoh; and Moses tossed it toward the sky, and it became boils breaking out with sores on every person and animal. ¹¹The soothsayer priests could not stand before Moses because of the boils, for the boils were on the soothsayer priests as well as on all the Egyptians. ¹²But the Lord hardened Pharaoh’s heart, and he did not listen to them, just as the Lord had spoken to Moses.