Exodus 8:11-15

11The frogs will leave you and your houses and leave your servants and your people; they will remain only in the Nile.”

12So Moses and Aaron left Pharaoh, and Moses cried out to the Lord [as he had agreed to do] concerning the frogs which God had inflicted on Pharaoh.

13The Lord did as Moses asked, and the frogs died out of the houses, out of the courtyards and villages, and out of the fields.

14So they piled them up in heaps, and the land was detestable and stank.

15But when Pharaoh saw that there was [temporary] relief, he hardened his heart and would not listen or pay attention to them, just as the Lord had said.