(22) Israel is my son.--Compare Hosea 11:1. This tender relation, now first revealed, is not a mere metaphor, meaning "as dear to me as a son," but a reality. The Israel of God enjoys the sonship of adoption by being taken into the True Son, and made one with Him (Romans 8:14-17).

My first ? born.--Admitted to sonship in the Messiah before the other nations of the earth.

Verse 22. - Thou shalt say unto Pharaoh, Israel is my son. This would be addressing Pharaoh in language familiar to him. Each Egyptian monarch of this period was accustomed to style himself, "son of the Sun," and to claim and expect the constant favour and protection of his divine parent. It was also quite within the range of Egyptian ideas that God should declare himself by word of mouth to his special favourites, and give directions as to their actions. (See 'Records of the Past,' vol. 4. p. 43.) My firstborn. Not only "as dear to me as to a father his firstborn" (Kalisch), but the only nation that I have adopted, and taken into covenant, so as to be unto me "a peculiar people above all the nations that are upon the earth" (Deuteronomy 14:2). Israel's sonship is here mentioned for the first time.

4:18-23 After God had appeared in the bush, he often spake to Moses. Pharaoh had hardened his own heart against the groans and cries of the oppressed Israelites; and now God, in the way of righteous judgment, hardens his heart against the teaching of the miracles, and the terror of the plagues. But whether Pharaoh will hear, or whether he will forbear, Moses must tell him, Thus saith the Lord. He must demand a discharge for Israel, Let my son go; not only my servant, whom thou hast no right to detain, but my son. It is my son that serves me, and therefore must be spared, must be pleaded for. In case of refusal I will slay thy son, even thy first-born. As men deal with God's people, let them expect so to be dealt with.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.