Exodus 8:8

Then Pharaoh called for Moses and Aaron, and said, Intreat the LORD, that he may take away the frogs from me, and from my people; and I will let the people go, that they may do sacrifice unto the LORD.

Pharaoh called ... Entreat the Lord. The frog, which was now used as an instrument of affliction and punishment, whether from reverence or abhorrence, was an object of national superstition with the Egyptians. It was an emblem of Osiris, and the god Ptha was represented with a frog's head. The significance of this second plague, therefore, appears in its being a severe rebuke to the Egyptians for their reptile worship. But the vast numbers of the frogs, together with their stench, made them an intolerable nuisance, so that the king was so far humbled as to promise that, if Moses would intercede for their removal, he would consent to the departure of Israel; and in compliance with this appeal they were withdrawn at the very hour named by the monarch himself.