'Dust of the Earth' in the Bible

And Jehovah said unto Moses, Say unto Aaron, Stretch out thy rod, and smite the dust of the earth, that is may become lice throughout all the land of Egypt.

And they did so; for Aaron stretched out his hand with his rod, and smote the dust of the earth, and it became lice in man, and in beast; all the dust of the land became lice throughout all the land of Egypt.