Exodus 9:10-12

Revised Standard Version

¹⁰ So they took ashes from the kiln, and stood before Pharaoh, and Moses threw them toward heaven, and it became boils breaking out in sores on man and beast. ¹¹ And the magicians could not stand before Moses because of the boils, for the boils were upon the magicians and upon all the Egyptians. ¹² But the Lord hardened the heart of Pharaoh, and he did not listen to them; as the Lord had spoken to Moses.