6:10–30  The remainder of this chapter establishes Aaron’s call and credentials. The genealogy functions mainly to demonstrate his legitimacy as a leader with Moses. The narrative structure ingeniously serves this purpose, as it begins and ends with Moses’ concern about his faltering lips (vv. 12, 30)—which makes Aaron’s presence necessary. The Lord’s instructions to Moses to speak to Pharaoh king of Egypt also frame this section (vv. 10–11 and 28–29). This inclusio (found within the chiastic framework above), or matching thematic beginning and ending, to the genealogy can be further diagrammed as follows:

B “Faltering lips,” speak to the king of Egypt (vv. 10–12)
C Formal introduction: Moses and Aaron (v. 13)
D Genealogy of Aaron (vv. 14–25)
C′ Formal conclusion: Aaron and Moses, Moses and Aa…