Exodus 8:10-12

10They piled them together in large heaps, and the land stank.

11But when Pharaoh saw that there was relief, he hardened his heart and did not listen to them—just as Adonai had said.

12So Adonai said to Moses, “Tell Aaron, ‘Stretch out your staff and strike the dust of the earth, and it will become gnats throughout all the land of Egypt.’”