Now therefore go is a command, spoken perhaps with some impatience. One may also express this idiomatically as “So, get going [or, moving].” I will be with your mouth is literal and may sound awkward; it means, as Good News Translation puts it, “I will help you to speak.” And teach you what you shall speak does not suggest special instruction in advance, but rather “I will tell you what to say” at the right time.

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .