Why was Moses insecure about confronting Pharaoh?
Moses had spent forty years on the backside of the desert herding sheep, with almost no contact with public or populated areas. That isolation left him timid and insecure, so when commissioned to confront Pharaoh, he still claimed he could not do it.
Les explains that Moses had been commissioned by God to go confront Pharaoh for the distinct purpose of bringing Israel out of bondage. But Moses faced a difficulty: overcoming his own timidity. At Exodus 4:10 he was still claiming he could not do it. Les says the reason is that Moses had been 40 years on the backside of the desert herding sheep, with almost no contact with public or populated areas, and consequently had become insecure.