Exodus 9:10-12

Amplified Bible, Classic Edition

¹⁰ So they took ashes or soot of the kiln and stood before Pharaoh; and Moses threw them toward the sky, and it became boils erupting in sores on man and beast.

¹¹ And the magicians could not stand before Moses because of their boils; for the boils were on the magicians and all the Egyptians.

¹² But the Lord hardened the heart of Pharaoh, making it strong and obstinate, and he did not listen to them or heed them, just as the Lord had told Moses.