'Dust' in the Bible

Then the Lord said to Moses, “Tell Aaron: Stretch out your staff and strike the dust of the earth, and it will become gnats throughout the land of Egypt.”

And they did this. Aaron stretched out his hand with his staff, and when he struck the dust of the earth, gnats were on man and beast. All the dust of the earth became gnats throughout the land of Egypt.

It will become fine dust over the entire land of Egypt. It will become festering boils on man and beast throughout the land of Egypt.”