'Dust of the Earth' in the Bible

And the Lord said to Moses, Say to Aaron, Let your rod be stretched out over the dust of the earth so that it may become insects through all the land of Egypt.

And they did so; and Aaron, stretching out the rod in his hand, gave a touch to the dust of the earth, and insects came on man and on beast; all the dust of the earth was changed into insects through all the land of Egypt.