And the king of Egypt said unto them. It is surprising that the king, in the excess of his arrogance, did not more cruelly entreat these servants of God, whom he accounted the ringleaders of sedition. But he was undoubtedly restrained by God from proceeding at once to destroy them. By his pertinacity in resisting their departure, he will more clearly shew by and bye how important to his interests he considered it that the people should remain in Egypt; how comes it then that he is contented with verbal reproof, and refrains from shedding their blood, if it were not that God protected his servants under the shield of His defense? He harshly reproves them, indeed, and condemns them to the same labors, by which the rest of the people were oppressed; but since it is notorious that moderate rigor never satisfies tyrants, we conclude that they were preserved under the guardianship of God, and would otherwise have died a hundred times over. But let us learn from his accusation against them, as the promoters of rebellion, to bear patiently, after their example, calumnies and false imputations; only, in reliance on God's command, let us be fully conscious that we are unjustly accused. The next verse, wherein he says, that "the people of the land are now many," is intended to aggravate their guilt; both because they would inflict a deeper injury on the public, than as if they had withheld a few from their work; and also, because, by inflaming a large number of people, they would bring greater danger on the country.

Let - i. e. hinder.

Wherefore do ye, Moses and Aaron - He hints that the Hebrews are in a state of revolt, and charges Moses and Aaron as being ringleaders of the sedition. This unprincipled charge has been, in nearly similar circumstances, often repeated since. Men who have labored to bring the mass of the common people from ignorance, irreligion, and general profligacy of manners, to an acquaintance with themselves and God, and to a proper knowledge of their duty to him and to each other, have been often branded as being disaffected to the state, and as movers of sedition among the people! See Clarke on Exodus 5:17 (note).
Let the people - תפריעו taphriu, from פרע para, to loose or disengage, which we translate to let, from the Anglo-Saxon lettan, to hinder. Ye hinder the people from working. Get ye to your burdens. "Let religion alone, and mind your work." The language not only of tyranny, but of the basest irreligion also.

And the king of Egypt said to them,.... For he was not struck dumb, as Artapanus (g), afore cited writer, says:
wherefore do ye, Moses and Aaron, let the people from their works? as they did when they gathered them together, and wrought signs before them; which Pharaoh it seems had heard of, and had got their names very readily:
get you unto your burdens; meaning not Moses and Aaron, ordering them to go about their private and family business, but the people they represented, and on whose account they came; and it is highly probable the elders of the people, at least some of them, were with them, to whom these words might be more particularly directed. See Exodus 3:18.
(g) Ut supra. (Apud Euseb. Praepar. Evangel. l. 9. c. 27. p. 434.)

Wherefore do ye, Moses and Aaron, let the people from their works? &c.--Without taking any notice of what they had said, he treated them as ambitious demagogues, who were appealing to the superstitious feelings of the people, to stir up sedition and diffuse a spirit of discontent, which spreading through so vast a body of slaves, might endanger the peace of the country.

But Pharaoh would hear nothing of any worship. He believed that the wish was simply an excuse for procuring holidays for the people, or days of rest from their labours, and ordered the messengers off to their slave duties: "Get you unto your burdens." For as the people were very numerous, he would necessarily lose by their keeping holiday. He called the Israelites "the people of the land," not "as being his own property, because he was the lord of the land" (Baumgarten), but as the working class, "land-people," equivalent to "common people," in distinction from the ruling castes of the Egyptians (vid., Jeremiah 52:25 : Ezekiel 7:27).