Exodus 9:6-9

6So the Lord did this thing on the next day, and 1all the livestock of Egypt died; 2but not one of the livestock of the sons of Israel died. 7And Pharaoh sent men, and they learned that, behold, not even one of the livestock of Israel was dead. But 3the heart of Pharaoh was 4hardened, and he did not let the people go.

8Then the Lord said to Moses and Aaron, “Take for yourselves handfuls of soot from a kiln, and Moses shall toss it toward the sky in the sight of Pharaoh. 9Then it will become fine dust over all the land of Egypt, and will turn into 5boils breaking out with sores on every person and animal through all the land of Egypt.”