Exodus 8:9

8:9 Moses said to Pharaoh, “You may have the honor over me – when shall I pray for you, your servants, and your people, for the frogs to be removed from you and your houses, so that they will be left only in the Nile?”

Exodus 8:28-29

8:28 Pharaoh said, “I will release you so that you may sacrifice to the Lord your God in the desert. Only you must not go very far. Do pray for me.”

8:29 Moses said, “I am going to go out from you and pray to the Lord, and the swarms of flies will go away from Pharaoh, from his servants, and from his people tomorrow. Only do not let Pharaoh deal falsely again by not releasing the people to sacrifice to the Lord.”