Exodus 8:9-10

9Moses said to Pharaoh, ‘I will let you choose the time when I should pray to God. Then I will ask God to do this for you, for your servants and for your people. I will ask God to remove the frogs from you and from all your houses. The frogs will remain only in the Nile river.’

10Pharaoh said, ‘Do it tomorrow.’ Moses answered, ‘I will do what you have asked. Then you will know that there is nobody like the Lord our God.