Read Exodus 3
I think most people in the educated world have heard the story of the burning bush. I have a slightly differing opinion, just a thought. What if the bush wasn't actually burning but God was standing behind the bush and His shikinah glory was shining through? We're taught in many places that man may not look directly at God, what if God put this bush between himself and Moses? At that time the only concept of light would come either form the sun, the moon, or a fire. So if a bush is lit up it must be on fire right? Just a thought, could be wrong. In any case the bush isn't important, it's the conversation.
God says to do this and Moses says I can't. God says, I'll take care of the details and Moses says I still can't. Ever had that conversation with God? You can't win, I do sometimes wonder if God enjoys the conversation anyway.