Else, if thou wilt not let my people go, behold, I will send swarms of flies upon thee, and upon thy servants, and upon thy people, and into thy houses: and the houses of the Egyptians shall be full of swarms of flies, and also the ground whereon they are. Swarms of flies upon thee - It is not easy to ascertain the precise meaning of the original word הערב hearob; as the word comes from ערב arab, he mingled, it may be supposed to express a multitude of various sorts of insects. And if the conjecture be admitted that the putrid frogs became the occasion of this plague, (different insects laying their eggs in the bodies of those dead animals, which would soon be hatched, see on Exodus 8:14 (note)), then the supposition that a multitude of different hinds of insects is meant, will seem the more probable. Though the plague of the locusts was miraculous, yet God both brought it and removed it by natural means; see Exodus 10:13-19.
Bochart, who has treated this subject with his usual learning and ability, follows the Septuagint, explaining the original by κυνομυια, the dog-fly; which must be particularly hateful to the Egyptians, because they held dogs in the highest veneration, and worshipped Anubis under the form of a dog. In a case of this kind the authority of the Septuagint is very high, as they translated the Pentateuch in the very place where these plagues happened. But as the Egyptians are well known to have paid religious veneration to all kinds of animals and monsters, whence the poet: -
Omnigenumque deum monstra, et latrator Anubis,
I am inclined to favor the literal construction of the word: for as ערב ereb, Exodus 12:38, expresses that mixed multitude of different kinds of people who accompanied the Israelites in their departure from Egypt; so here the same term being used, it may have been designed to express a multitude of different kinds of insects, such as flies, wasps, hornets, etc., etc. The ancient Jewish interpreters suppose that all kinds of beasts and reptiles are intended, such as wolves, lions, bears, serpents, etc. Mr. Bate thinks the raven is meant, because the original is so understood in other places; and thus he translates it in his literal version of the Pentateuch: but the meaning already given is the most likely. As to the objection against this opinion drawn from Exodus 8:31, there remained not one, it can have very little weight, when it is considered that this may as well be spoken of one of any of the different kinds, as of an individual of one species.