Exodus 4:10
8 “If they do not believe you or pay attention to the former sign, then they may believe the latter sign. 9 And if they do not believe even these two signs or listen to you, then take some water from the Nile and pour it out on the dry ground. The water you take out of the Nile will become blood on the dry ground.” 10 Then Moses said to the Lord, “O my Lord, I am not an eloquent man, neither in the past nor since you have spoken to your servant, for I am slow of speech and slow of tongue.” 11 The Lord said to him, “Who gave a mouth to man, or who makes a person mute or deaf or seeing or blind? Is it not I, the Lord? 12 So now go, and I will be with your mouth and will teach you what you must say.”
Jeremiah 1:6
4 The Lord’s message came to me, 5 “Before I formed you in your mother’s womb, I chose you. Before you were born, I set you apart. I appointed you to be a prophet to the nations.” 6 I answered, “Oh, Sovereign Lord, Really I do not know how to speak well enough for that, for I am too young.” 7 The Lord said to me, “Do not say, ‘I am too young.’ But go to whomever I send you and say whatever I tell you. 8 Do not be afraid of those to whom I send you, for I will be with you to protect you,” says the Lord.
Notes and References
"... let us consider what sorts of criteria might establish that the parallels between these texts were caused by P’s dependence on Exodus 3:1–4:17 rather than their dependence on a common precursor or the dependence of Exodus 3:1–4:17 on P. Sometimes one can decide such cases on the basis of expansion by one text of wording found in its parallel, but Exodus 3:1–4:17 lacks the sorts of extensive verbal parallels with P that would allow such an approach. One criterion that can be helpful in this case, however, is the presence of blind motifs in one text that are integral to the other. For example, one element that is integral to Exodus 3:1–4:17 as a whole is its presentation of both Moses and Aaron as prophetic figures, both through the elaboration of the prophetic call-narrative pattern in describing YHWH’s commissioning of Moses and through specific echoes of the late-Jeremiah call narrative (Jeremiah 1:4–10) in describing the commissioning of Aaron. The Priestly material in 6:12–13 shares the idea that Aaron was appointed because of Moses’s problems with speech (Exodus 4:10b-12; compare Jeremiah 1:6), and its resumptive repetition in 6:30–7:2 even names Aaron as a “prophet” (7:1). Otherwise, however, the prophetic elements so central to Exodus 3:1–4:17 are marginal in corresponding P materials. This is an indicator that, overall, P materials are dependent on Exodus 3:1–4:17, rather than vice versa. It is easier to suppose that the otherwise unmotivated themes of Moses’s difficulty with speaking (Exodus 6:12–13) and Aaron’s “prophet” status (vis-à-vis Moses as “God” to him in Exodus 7:1; compare 4:16) in P materials are faint echoes of the thoroughly prophetic presentation of both figures in Exodus 3:1–4:17 than that the detailed prophetic elements and resonances with Jeremiah 1:4–10 in Exodus 3:1–4:17 unfolded as elaborations on these minor elements in the P stratum ..."
Carr, David McLain The Formation of the Hebrew Bible: A New Reconstruction (pp. 143-143) Oxford University Press, 2011