Exodus 9:8

The Sixth Blow: Boils

9:8 Then the Lord said to Moses and Aaron, “Take handfuls of soot from a furnace, and have Moses throw it into the air while Pharaoh is watching.

Exodus 9:10

9:10 So they took soot from a furnace and stood before Pharaoh, Moses threw it into the air, and it caused festering boils to break out on both people and animals.