Once Aaron is appointed the spokesman, the Holy One explains how the chain of communication will actually work. Targum Pseudo-Jonathan preserves the threefold structure: thou shalt speak with him, and put the matter in his mouth, and My Word shall be with the word of thy mouth, and with the word of his mouth.
Trace the flow. God's Memra — Word — comes to Moses. Moses transmits the matter to Aaron. Aaron speaks to Pharaoh and the people. But here is the hidden line: the Memra accompanies both mouths along the way. It is not passed like a baton, fading at each handoff. It is present at every station.
Why Two Mouths Rather Than One
A cleaner arrangement would have been to heal Moses' stammer. The sages of the Targumic tradition ask why God chooses the more complicated solution. The answer they suggest: because prophecy was never meant to be a solo performance. The covenant needs witnesses who overlap — the priest beside the prophet, the elder brother beside the younger, the fluent mouth beside the lame one.
The Targum closes with: I will instruct you what you are to do. Note the plural. You — both of them. The instruction is addressed not to Moses alone but to the team. Moses and Aaron will be trained together, sent together, and judged together.
The takeaway: leadership in the Jewish imagination is never solitary. The Memra of God rides on two mouths at once, because a nation that has been silent for four hundred years needs at least two voices to speak it back into history.