4:16Spokesman: lit., “mouth”; Aaron was to serve as a mouthpiece for Moses, as a prophet does for God; hence the relation between Moses and Aaron is compared to that between God and his prophet: Moses “will be as God to,” i.e., lit., “will become God for him.” Cf. 7:1.
7:1Prophet: Hebrew nabi, one who can legitimately speak for God and in God’s name to another or others. Just as God spoke to Moses, so Moses will speak to Aaron, who will be a “prophet” to Pharaoh. Cf. 4:16.