Exodus 8:18-19

18The soothsayer priests tried with their secret arts to produce 1gnats, but 2they could not; so there were 3gnats on every person and animal. 19Then the soothsayer priests said to Pharaoh, “4This is the finger of God.” But Pharaoh’s heart was 5hardened, and he did not listen to them, just as the Lord had said.