'Dust' in the Bible

Then the Lord said to Moses, “Say to Aaron, ‘Stretch out your staff and strike the dust of the ground, and it will become [biting] gnats (lice) throughout the land of Egypt.’”

They did so; Aaron stretched out his hand with his staff and struck the dust of the earth, and there were [biting] gnats on man and animal. All the dust of the land became gnats through all the land of Egypt.

It will become fine dust over the entire land of Egypt, and it will become boils breaking out in sores on man and animal in all the land [occupied by the Egyptians].”