Exodus 8:7-9

7But the magicians did the same things by their secret arts; they also made frogs come up on the land of Egypt.

8Pharaoh summoned Moses and Aaron and said, “Pray to the Lord to take the frogs away from me and my people, and I will let your people go to offer sacrifices to the Lord.”

9Moses said to Pharaoh, “I leave to you the honor of setting the time for me to pray for you and your officials and your people that you and your houses may be rid of the frogs, except for those that remain in the Nile.”