Exodus 9:8-17

8And the LORD said to Moses and to Aaron, Take to you handfuls of ashes of the furnace, and let Moses sprinkle it toward heaven in the sight of Pharaoh. 9And it shall become small dust in all the land of Egypt, and shall be a boil breaking forth with sores upon man, and upon beast, throughout all the land of Egypt. 10And they took ashes of the furnace, and stood before Pharaoh; and Moses sprinkled it toward heaven; and it became a boil breaking forth with sores upon man, and upon beast. 11And the magicians could not stand before Moses because of the boils; for the boil was upon the magicians, and upon all the Egyptians. 12And the LORD hardened the heart of Pharaoh, and he hearkened not to them; as the LORD had spoken to Moses.

13And the LORD said to Moses, Rise early in the morning, and stand before Pharaoh, and say to him, Thus saith the LORD God of the Hebrews, Let my people go, that they may serve me. 14For I will at this time send all my plagues upon thy heart, and upon thy servants, and upon thy people; that thou mayest know that there is none like me in all the earth. 15For now I will stretch out my hand, that I may smite thee and thy people with pestilence; and thou shalt be cut off from the earth. 16And in very deed for this cause have I raised thee up, to show in thee my power; and that my name may be declared throughout all the earth.1 17As yet dost thou exalt thyself against my people, that thou wilt not let them go?