Exodus 8:2

2. I will smite all thy borders with frogs Several species of frogs are found in Egypt, and they are specially abundant in September, filling the lakes and ponds left by the retiring inundation . In the spawning season the waters are so filled with them that a bowl of water taken up almost anywhere will be found to contain tadpoles, yet there is no other instance of their becoming a plague to the inhabitants, although there are traditions of similar plagues in other countries . But a superhuman influence is here most evident . The frog is an amphibious animal, living in the water or in moist, marshy lands . For these animals, then, to leave the river and river banks, and swarm up into the cities, which were situated in the edge of the dry desert, into the very houses, and into the driest places in the houses, as the beds, kneading-troughs, and ovens, was a miraculous manifestation most striking and alarming. The atmosphere of Egypt is always remarkably dry, rain being very rare except on the seacoast, sothat usually a frog could live but a very short time in an Egyptian street or house. If, now, heavy clouds and rains accompanied this visitation, in order to enable the reptiles to live in the cities, as seems likely, the supernatural character of the infliction would be still more marked.

This was also in several ways a blow at the Egyptian idolatry. The judgment comes, as before, from the deified Nile, and comes in one of their sacred animals. The frog was an emblem of the great god Pthah, the tutelar god of Memphis, and the principal divinity of Lower Egypt, so that their protecting deity now became to the Memphites a loathsome abomination. Lepsius traces this form of idolatry to the most ancient nature worship of the land. Mariette has published a curious vignette from the monuments, representing king Seti offering two vases of wine to a frog enshrined in a small chapel. Brugsch also shows that in the district of Sah the Egyptians worshipped a goddess with a frog’s head, whom they called Heka.