Exodus 9:6-9

6Then the next day, Adonai did the deed. All the cattle of Egypt died, yet of the cattle of Bnei-Yisrael, not one died.

7When Pharaoh inquired, there was not so much as one of the cattle of Bnei-Yisrael dead. But the heart of Pharaoh was stubborn, and he did not let the people go.

8Then Adonai said to Moses and Aaron, “Take handfuls of soot from the furnace, and have Moses throw it heavenward in the sight of Pharaoh.

9It will become fine dust over all the land of Egypt, and will become boils erupting with sores on both men and animals throughout all the land.”