Another narrative discrepancy that occurs from the combination of our duplicate stories is the, now, doublet of Aaron’s commission.
Since P’s story of the revelation of Yahweh and commission of Aaron (Ex 6:2-7:13) is placed after E’s version, where both the revelation of Yahweh and commission of Aaron have already been narrated (Ex 4:1-30), these events in the current version of the text happen twice.
Aaron is therefore commissioned both before (4:14-16) Moses is sent to the people (4:27-31), in an attempt to solve the problem of Moses’ “heavy mouth and heavy tongue” (4:10), and after he initially fails (5:4-5, 6:9). Yet the second commission, P’s version, displays no knowledge of the previous failure on the part of Moses, that is in E’s version. P wrote his version as a new story which highlighted the role of Aaron. However, a later redactor, most likely of the same Aaronid guild, placed P’s version of the commission of Aaron after E’s version and thereby created a new narrative element: Aaron is recommissioned because Moses had previously failed.
The issue, moreover, is not one of a mere doublet that has the unfortunate result of creating the scene twice, but is one of stark differences in terms of creating authoritative claims between the two stories. In E, Aaron is commissioned because Moses suffers from being “heavy of mouth and of tongue” (4:10), and he is commissioned to help Moses speak to Israel (4:14-16, 4:27-31). In the redacted text, however, Aaron is recommissioned because Moses has failed. Additionally, Moses is just not “heavy of mouth and of tongue” but according to the Priestly writer religiously unfit for the task: he is “uncircumcised of lips” (#93). The author of P, in other words, against the older E tradition, attempts to authenticate Aaron as the more authoritative figure. The word choice of P, Moses’ “uncircumcised lips,” is not merely a rearticulation of E’s Moses’ inability to speak, but one which cleverly implies Moses is unclean for the office.
In fact, the way in which P’s version was added into the narrative strengthens Aaron’s supremacy: only with Aaron at his side can Moses have success with the Pharaoh.