Israel is my son, even my first-born. God thus refutes, by anticipation, the only pretext by which Pharaoh could justify his refusal to let the people go. For Jacob had spontaneously submitted himself and all his family to his government; he had then free power to retain the people, which, by the common law of nations, was subject to the dominion of Egypt. But if it be an act of impiety to violate the ordinance instituted by God, the demand of Moses might appear improper, that the legitimate authority of the king should be abolished against his own will. For what was the object of proposing the departure of the people, except to compel the king to renounce his own authority? In order, then, to shew that he took nothing away unjustly or unreasonably from Pharaoh, God alleges the privilege by which the Israelites were excepted from ordinary laws; for by calling them His sons, He claims liberty for them; since it would be absurd that God himself, the supreme Ruler of heaven and earth, should be deprived of the sons whom He had deigned to adopt. He, therefore, indirectly compares his own paternal power with Pharaoh's earthly rule; because nothing could be less reasonable than that a mortal should refuse to yield to the Maker of himself and all the world. Still this is not applicable to all believers in general; as if it were wrong for them to be subject to kings, or as if their temporal subjection deprived them of their inheritance of the world; but mention is here only made of the special prerogative with which God had honored the posterity of Abraham, when he gave them the dominion of the land of Canaan. Therefore, not content with the simple appellation of son, He calls Israel his first-born. By this honorable title He unquestionably prefers him to the other nations; as though He had said, that he was raised to the degree of the primogeniture, and was superior to all the world. This passage, then, may be accommodated to the calling of the Gentiles, whom God had already decreed to bring into fellowship with his elect people, so that, although they were younger, they might be united with his first-born. I allow, indeed, that all the race of Adam was then cast off; but, because Adam was made in the image of God, his posterity were always reckoned, in a certain sense, to be the children of God; for, whilst I readily admit that the holy offspring of Abraham are here compared with the nations who at that time were still heathen, and that in this respect they are called his first-born, because they are pre-eminent in dignity; still we must come to Christ, the only head, in order that the adoption should be sure. For we must hold fast to that statement of St. Paul, that the blessing of Abraham was not promised to his seeds, but to his seed; because not all that sprang from his flesh are accounted to be children, but those that were called; as Isaac, Ishmael being rejected, and as Jacob, Esau being passed by. (Galatians 3:16; Romans 9:6.) But Christ is the root of our calling. Therefore, what in Hosea is spoken, as here, of the whole people, Matthew limits to Christ; and justly, since upon Him alone the grace of adoption is founded. (Hosea 11:1; Matthew 2:15.)

My firstborn - The expression would be perfectly intelligible to Pharaoh, whose official designation was "son of Ra." In numberless inscriptions the Pharaohs are styled "own sons" or "beloved sons" of the deity. It is here applied for the first time to Israel; and as we learn from Exodus 4:23, emphatically in antithesis to Pharaoh's own firstborn.

Israel is my son, even my firstborn - That is, The Hebrew people are unutterably dear to me.

And thou shalt say unto Pharaoh, Thus saith the LORD, Israel [is] my son, [even] my (k) firstborn:
(k) Meaning, most dear to him.

And thou shall say unto Pharaoh,.... When arrived in Egypt, and in his presence:
thus saith the Lord; he was to declare to him that he came in his name, and by his orders, and, as an ambassador of his, required the dismission of the children of Israel out of Egypt:
Israel is my son, even my firstborn; as dear to him as a man's firstborn is, or as his only son: adoption is one of the privileges peculiar to Israel after the flesh, even national adoption, with all the external privileges appertaining to it, Romans 9:4.

Thus saith the Lord - This is the first time that preface is used by any man, which afterwards is used so frequently by all the prophets: Israel is my son, my first - born - Precious in my sight, honourable, and dear to me.