Here is the story of the plague of flies, in which we are told,

I.How it was threatened, like that of frogs, before it was inflicted. Moses is directed (Exo 8:20) to rise early in the morning, to meet Pharaoh when he came forth to the water, and there to repeat his demands. Note, 1. Those that would bring great things to pass for God and their generation must rise early, and redeem time in the morning. Pharaoh was early up at his superstitious devotions to the river; and shall we be for more sleep and more slumber when any service is to be done which would pass well in our account in the great day? 2. Those that would approve themselves God's faithful servants must not be afraid of the face of man. Moses must stand before Pharaoh, proud as he was, and tell him that which was in the highest degree humbling, must challenge him (if he refused to release his captives) to engage with any army of flies, which would obey God's orders of Pharaoh would not. See a similar threatening, Isa 7:18, The Lord will hiss (or whistle) for the fly and the bee, to come and serve his purposes.

II.How the Egyptians and the Hebrews were to be remarkably distinguished in this plague, Exo 8:22, Exo 8:23. It is probable that this distinction had not been so manifest and observable in any of the foregoing plagues as it was to be in this. Thus, as the plague of lice was made more convincing than any before it, by its running the magicians aground, so was this, by the distinction made between the Egyptians and the Hebrews. Pharaoh must be made to know that God is the Lord in the midst of the earth; and by this it will be known beyond dispute. 1. Swarms of flies, which seem to us to fly at random, shall be manifestly under the conduct of an intelligent mind, while they are above the direction of any man. "Hither they shall go," says Moses, "and thither they shall not come;" and the performance is punctually according to this appointment, and both, compared, amount to a demonstration that he that said it and he that did it was the same, even a Being of infinite power and wisdom. 2. The servants and worshippers of the great Jehovah shall be preserved from sharing in the common calamities of the place they live in, so that the plague which annoys all their neighbours shall not approach them; and this shall be an incontestable proof that God is the Lord in the midst of the earth. Put both these together, and it appears that the eyes of the Lord run to and fro through the earth, and through the air too, to direct that which to us seems most casual, to serve some great designed end, that he may show himself strong on the behalf of those whose hearts are upright with him, Ch2 16:9. Observe how it is repeated: I will put a division between my people and thy people Exo 8:23. Note, The Lord knows those that are his, and will make it appear, perhaps in this world, certainly in the other, that he has set them apart for himself. A day will come when you shall return and discern between the righteous and the wicked (Mal 3:18), the sheep and the goats (Mat 25:32; Eze 34:17), though now intermixed.

III.How it was inflicted, the day after it was threatened: There came a grievous swarm of flies (Exo 8:24), flies of divers sorts, and such as devoured them, Psa 78:45. The prince of the power of the air has gloried in being Beelzebub - the god of flies; but here it is proved that even in that he is a pretender and a usurper, for even with swarms of flies God fights against his kingdom and prevails.

IV.How Pharaoh, upon this attack, sounded a parley, and entered into a treaty with Moses and Aaron about a surrender of his captives: but observe with what reluctance he yields.

1.He is content they should sacrifice to their God, provided they would do it in the land of Egypt, Exo 8:25. Note, God can extort a toleration of his worship, even from those that are really enemies to it. Pharaoh, under the smart of the rod, is content they should do sacrifice, and will allow liberty of conscience to God's Israel, even in his own land. But Moses will not accept his concession; he cannot do it, Exo 8:26. It would be an abomination to God should they offer the Egyptian sacrifices, and an abomination to the Egyptians should they offer to God their own sacrifices, as they ought; so that they could not sacrifice in the land without incurring the displeasure either of their God or of their task-masters; therefore he insists: We will go three days' journey into the wilderness, Exo 8:27. Note, Those that would offer an acceptable sacrifice to God must, (1.) Separate themselves from the wicked and profane; for we cannot have fellowship both with the Father of lights and with the works of darkness, both with Christ and with Belial, Co2 6:14, etc.; Psa 26:4, Psa 26:6. (2.) They must retire from the distractions of the world, and get as far as may be from the noise of it. Israel cannot keep the feast of the Lord either among the brick-kilns or among the flesh-pots of Egypt; no, We will go into the wilderness, Hos 2:14; Sol 7:11. (3.) They must observe the divine appointment: "We will sacrifice as God shall command us, and not otherwise." Though they were in the utmost degree of slavery to Pharaoh, yet in the worship of God, they must observe his commands and not Pharaoh's.

2.When this proposal is rejected, he consents for them to go into the wilderness, provided they do not go very far away, not so far but that he might fetch them back again, Exo 8:28. It is probable he had heard of their design upon Canaan, and suspected that if once they left Egypt they would never come back again; and therefore, when he is forced to consent that they shall go (the swarms of flies buzzing the necessity in his ears), yet he is not willing that they should go out of his reach. Thus some sinners who, in a pang of conviction, part with their sins, yet are loth they should go very far away; for, when the fright is over, they will return to them again. We observe here a struggle between Pharaoh's convictions and his corruptions; his convictions said, "Let them go;" his corruptions said, "Yet not very far away:" but he sided with his corruptions against his convictions, and this was his ruin. This proposal Moses so far accepted as that he promised the removal of this plague upon it, Exo 8:29 See here, (1.) How ready God is to accept sinners' submissions. Pharaoh does but say, Entreat for me (though it is with regret that he humbles so far), and Moses promises immediately, I will entreat the Lord for thee, that Pharaoh might see what the design of the plague was, not to bring him to ruin, but to bring him to repentance. With what pleasure did God say (Kg1 21:29), Seest thou how Ahab humbles himself? (2.) What need we have to be admonished that we be sincere in our submission: But let not Pharaoh deal deceitfully any more. Those that deal deceitfully are justly suspected, and must be cautioned not to return again to folly, after God has once more spoken peace. Be not deceived, God is not mocked; if we think to put a cheat upon God by a counterfeit repentance, and a fraudulent surrender of ourselves to him, we shall prove, in the end, to have put a fatal cheat upon our own souls.

Lastly,The issue of all was that God graciously removed the plague (Exo 8:30, Exo 8:31), but Pharaoh perfidiously returned to his hardness, and would not let the people go, Exo 8:32. His pride would not let him part with such a flower of his crown as his dominion over Israel was, nor his covetousness with such a branch of his revenue as their labours were. Note, Reigning lusts break through the strongest bounds, and make men impudently presumptuous and scandalously perfidious. Let not sin therefore reign; for, if it do, it will betray and hurry us to the grossest absurdities.

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 Exo 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 Exo 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, Exo 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 Exo 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.

And I will sever in that day the land of Goshen, in which my people dwell,.... Distinguish it from other parts of the land of Egypt:

that no swarms of flies shall be there; which was a very wonderful thing, and so the word may be rendered. "I will marvellously sever or separate" (o), and so the Targum of Jonathan, "I will do wonders or miracles in that day": as they were to make such a difference in one part of the country from another, and so near as Goshen was to the place where Pharaoh lived, and to bound and limit such sort of creatures as flies, which move swiftly from place to place, and particularly to keep the land of Goshen clear of them; when, as Bishop Patrick observes, it was a country that abounded with cattle, whose dung is apt to breed flies:

to the end thou mayest know that I am the Lord in the midst of the earth; he is God over all the earth, and rules as a King in the midst of it, and does whatsoever he pleases in it; see Psa 74:12 and in the midst of the land of Goshen where his people dwelt, and over whom he was King in a peculiar manner, and took a peculiar care of them, to protect and defend them; and which must the more vex and distress the Egyptians, when they saw the Israelites clear of those plagues they were afflicted with.

(o) "faciamque mirabilem", V. L. "miraculose agam", Fagius; "marvellously sever", Ainsworth.

PLAGUE OF FLIES. (Exo 8:20-32)

Rise up early . . . Pharaoh; lo, he cometh forth to the water, &c.--Pharaoh still appearing obdurate, Moses was ordered to meet him while walking on the banks of the Nile and repeat his request for the liberation of Israel, threatening in case of continued refusal to cover every house from the palace to the cottage with swarms of flies--while, as a proof of the power that accomplished this judgment, the land of Goshen should be exempted from the calamity. The appeal was equally vain as before, and the predicted evil overtook the country in the form of what was not "flies," such as we are accustomed to, but divers sorts of flies (Psa 78:45), the gad fly, the cockroach, the Egyptian beetle, for all these are mentioned by different writers. They are very destructive, some of them inflicting severe bites on animals, others destroying clothes, books, plants, every thing. The worship of flies, particularly of the beetle, was a prominent part of the religion of the ancient Egyptians. The employment of these winged deities to chastise them must have been painful and humiliating to the Egyptians while it must at the same time have strengthened the faith of the Israelites in the God of their fathers as the only object of worship.