I will be with thy mouth and with his mouth Even Aaron that could speak well, yet could not speak to purpose, unless God were with his mouth; without the constant aids of divine grace, the best gifts will fail. Instead of God To teach and to command him.
Related Commentaries of Exodus 4:15
Exodus 4:15-16
15 And thou shalt speak unto him, and put words in his mouth: and I will be with thy mouth, and with his mouth, and will teach you what ye shall do.
16 And he shall be thy spokesman unto the people: and he shall be, even he shall be to thee instead of a mouth, and thou shalt be to him instead of God.