Exodus 4:21-23 J. The Death of Pharaoh's Firstborn is Threatened.
Exodus 4:22 f. seems to have been moved back hither from before Exodus 10:28 to serve as a general introduction to the Plagues, receiving Exodus 4:21 as preface. The portents of Exodus 4:21 are not the signs of Exodus 4:2-9 J, to be done for Israel's benefit, but those of Exodus 4:17 E, to be done with the rod before Pharaoh. With Exodus 4:22 cf. Hosea 11:2. The prophetic intuition which saw Yahweh's love for Israel as a father's for his firstborn became one of the grand commonplaces of Heb. religion. We find it christened in Galatians 3:26-29. It may have had its root in a cruder notion, found outside the OT, of a physical relation between a people and a divine ancestor, but in Israel, as Driver points out, the idea was spiritual.