Exodus 8:7Meaning & Commentary from the Church Fathers

Had the sages truly cherished Egypt, they would not have combined their whimsical visions with the genuine plagues inflicted by Moses. Thus, they failed to bring healing to Egypt, for they could not eradicate the plagues of Moses; nor did they inflict harm, as they presented mere illusions instead of authentic afflictions. They neither struck nor restored, as they could only offer fantasies. One species of fish perished, while a different kind of plague emerged, so that those not awakened by the death of the fish endured the torment of the living afflictions.

They had the ability to summon certain creatures from the water onto dry land; however, they were unable to take the frogs away from Egypt.