I. PHARAOH FINDS AS BEFORE THAT THERE IS NO ESCAPING FROM THE HANDS OF GOD. He is met at the brink of the river, and confronted with the old alternative - "Let my people go else," etc. (vers, 20, 21). The king, when he saw Moses, would have no difficulty in anticipating what was coming. The bitter greeting he would give him would be akin to that of Ahab to Elijah - "Hast thou found me, O mine enemy?"(1 Kings 21:20); nor would Moses' reply be very different from that given by the prophet - "I have found thee; because thou hast sold thyself to work evil in the sight of the Lord." What madness in the king to keep up this foolish, this suicidal contest! But the conflict of every sinner with Jehovah is of the same infatuated character. Stroke after stroke descends, yet impenitence is persevered in. Well may God say, "Why should ye be stricken any more?"(Isaiah 1:5.) His demand, through all, abides unchanged.

II. THE FOURTH PLAGUE SPRINGS FROM THE AIR. The sphere of judgment is widening and extending, taking in constantly new regions - water, earth, air. The voices that summon to repentance are heard from every side. A new demonstration of the universality of Jehovah's rule-of the unlimited sweep of his dominion (ver. 22). Flies are agents which God can employ as a scourge of nations still. We read of singular feats in the way of insect-taming; of flies, bees, and even lice being trained to obey orders, and go through wonderful evolutions. Man's power of control over these minute creatures is but a feeble image of the power exercised over them by God. He enrols them among his battalions, and uses them to execute his commissions.

III. A NEW SIGN IS THIS TIME GIVEN - THE SEVERANCE OF THE LAND OF GOSHEN FROM THE REST OF EGYPT (vers. 22, 23). The Israelites had probably been made fellow-sufferers with the Egyptians, at least in part, in the inconvenience experienced from the first three plagues. This was permitted, at once as a chastisement for their unbelief and murmurings, and as a purifying discipline. Nothing has been said as to the effect produced upon their minds by the outbreak of these terrific plagues; but they must have shown the Israelites the folly of their recent conduct, and wrought them up to a high pitch of expectation in the confidence that the day of their redemption was drawing near. With the production of this change of mind in the dwellers in Goshen, the nell for further inflictions upon them ceased, and a difference was thereafter put between them and the Egyptians. This astonishing separation was as clear a proof as could have been given of Jehovah's absoluteness in the government of the creatures, of the extent of his rule, and of the care he exercised over his chosen people. Possibly, Pharaoh had hitherto been taking encouragement from the fact that Israel was involved in the calamities. He may have been led to question:

1. God's power, seeing that he could not protect his own worshippers. It may have suggested itself to him that Jehovah's power was limited, and therefore might successfully be braved.

2. God's love for Israel. For if he loved them so much, why did he allow them to suffer? And if his interest in them was as weak as facts seemed to show, it was not impossible, if resistance was continued, that he might abandon them altogether.

3. The likelihood of God's proceeding to extremities. God, Pharaoh may have thought, must stop somewhere, else his own people will be destroyed together with mine. The need of protecting them is a safeguard against his proceeding to extremes with me. The severance now effected between Goshen and the rest of Egypt was a cruel blow to all such hopes. Thenceforward it was plain that God did care for Israel, that his power was as great as his/ore, and that whatever happened to Egypt, Israel was as safe as the pavilion of the Divine protection could make it. The fact is not without significance to ourselves. It teaches us that a deep and broad line of demarcation is really being put in God's thoughts between his own people and the rest of mankind, and that, whatever be the nature of his outward providence, he has their interests and well-being continually at heart. Those who encourage themselves in sin because they see that the righteous suffer with the wicked, and judge that this proves an absence of interest or care on the part of God, must submit to a great undeceiving. The last judgment will make a final separation (Matthew 25:31-35).

IV. THE FOURTH PLAGUE BROUGHT PHARAOH A SECOND TIME TO THE POINT OF SUBMISSION TO GOD'S COMMANDS. The separation of the territory of Israel seems greatly to have startled him, and he sent anew for Moses. The unwillingness of his mind to grant the required consent to the departure of the people is apparent from the interview.

1. Pharaoh proposes a compromise (Exodus 5:25). This is a common expedient with those who are hard pushed with questions of religion. It is, however, only a veil for the spirit of disobedience working underneath. The compromise proposed was unhesitatingly rejected by Moses. He had no authority to accept it. It was in its own nature an untenable one (ver. 26). Nothing was to be gained by accepting it. By standing firm to his demand, he was certain to get the whole of what he wanted (ver. 28), why then take a part? Had he accepted the compromise, it would probably only have embeldened Pharaoh to further resistance. God's servants will do well to imitate Moses in this distrust of compromises. Little good ever comes of them. Principle, not expediency, should rule the Christian's conduct. The intrusion of expediency into matters ecclesiastical has been a grievous source of weakness, of scandal, and of loss of spiritual power.

2. He ultimately yields. He concedes the whole demand; qualified only by the injunction not to go far away (ver. 28). The interview leaves on one's mind the impression of sincerity - of a real relenting, of however short a duration, on the part of Pharaoh. Just so much the more fatal to his spiritual life was the subsequent hardening.

V. THOUGH WARNED BY MOSES OF THE PERIL OF ACTING DECEITFULLY, PHARAOH ANEW HARDENED HIS HEART (ver. 32). Hardening, after the experience just described, may be regarded as almost settling Pharaoh's doom. He would soon be, if he was not already, irrecoverable. God had trusted him a second time, and this was the result. Obstinacy was passing into obduracy. - J.O.

1. Because both are guilty of sin.

2. Because both need correction and improvement.

3. Because life is a probation and a discipline.

II. IT IS AN EXCEPTIONAL METHOD OF THE DIVINE ADMINISTRATION TO EXEMPT THE GOOD FROM THE TRIALS AND RETRIBUTIONS OF THIS LIFE. "And I will put a division between My people and thy people."

1. Thus we see that there are times in this life when moral character gives exemption from severe retribution. This is the honour God places upon true moral goodness. In this way He occasionally shows His approval of it. Piety shields the house. It will protect a nation from the plague of God.

2. Thus we see that there are times in this life when God manifests to men His care for the good.

3. Thus we see that there are times in this life when God gives men a prophecy of the social equity in the world to come. Then Egypt will be ever separate from Goshen in character, as in retribution and reward. Heaven will adjust the moral relations of the universe.Lessons:

1. That continued sin must be visited by continued retribution.

2. That the providence of God is over the good to save them from pain.

3. That the wicked must see the worth of goodness.

(J. S. Exell, M. A.)