You are to speak to him and put the words in his mouth. I will help both of you to speak, and I will teach you what to do.
Moses persists in backward steps, and we cannot now call it humility but must own cowardice, slothfulness, and unbelief. He was a great mind but no orator, and thought himself unfit for great affairs; yet God often chooses those with fewest natural advantages, that His grace may shine the brighter. An unwilling mind will seize any sorry excuse rather than obey.
AI summary
Commenting on Exodus 4:10-17
And thou shalt speak unto him, and put words in his mouth,.... Or "things" (z), the matter and substance of what he should say, who being a man of words, an eloquent man, and a good spokesman, would put them into proper language, and express them fluently: and I will be with thy mouth, and with his mouth, and will teach you what ye shall...
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. (f) You will instruct him what to say.