16 So the Lord said to Moses, "Say to Aaron, 'Stretch out your rod, and strike the dust of the land, so that it may become lice throughout all the land of Egypt.' " 17 And they did so. For Aaron stretched out his hand with his rod and struck the dust of the earth, and it became lice on man and beast. All the dust of the land became lice throughout all the land of Egypt. 18 Now the magicians so worked with their enchantments to bring forth lice, but they could not. So there were lice on man and beast. 19 Then the magicians said to Pharaoh, "This is the finger of God." But Pharaoh's heart grew hard, and he did not heed them, just as the Lord had said.
Matthew Henry's Commentary on Exodus 8:16-19
Commentary on Exodus 8:16-19
(Read Exodus 8:16-19)
These lice were produced out of the dust of the earth; out of any part of the creation God can fetch a scourge, with which to correct those who rebel against him. Even the dust of the earth obeys him. These lice were very troublesome, as well as disgraceful to the Egyptians, whose priests were obliged to take much pains that no vermin ever should be found about them. All the plagues inflicted on the Egyptians, had reference to their national crimes, or were rendered particularly severe by their customs. The magicians attempted to imitate it, but they could not. It forced them to confess, This is the finger of God! The check and restraint put upon us, must needs be from a Divine power. Sooner or later God will force even his enemies to acknowledge his own power. Pharaoh, notwithstanding this, was more and more obstinate.