Exodus 8:24-27

24Pharaoh said, “I will let you go, so that you may sacrifice to Adonai your God in the wilderness. Only you must not go very far away. Pray for me.”

25So Moses said, “See, I am leaving you, and I will pray to Adonai that the swarm of flies will depart from Pharaoh, his servants and from his people tomorrow. However, let Pharaoh no longer deal deceitfully by not letting the people go sacrifice to Adonai.”

26Then Moses went out from Pharaoh and prayed to Adonai.

27Adonai acted according to the word of Moses, and removed the swarm of flies from Pharaoh, from his servants and from his people. Nothing remained.