'Dust' in the Bible

And Jehovah said to Moses, Say unto Aaron, Stretch out thy staff, and smite the dust of the earth, and it shall become gnats throughout the land of Egypt.

And they did so; and Aaron stretched out his hand with his staff, and smote the dust of the earth, and there arose gnats on man and on beast: all the dust of the land became gnats throughout the land of Egypt.

And it shall become fine dust over all the land of Egypt, and shall become boils on man and on cattle, breaking out with blisters, throughout the land of Egypt.