Ex 3:2-4
There an angel of the LORD appeared to him in fire flaming out of a bush. As he looked on, he was surprised to see that the bush, though on fire, was not consumed. So Moses decided, "I must go over to look at this remarkable sight, and see why the bush is not burned." When the LORD saw him coming over to look at it more closely, God called out to him from the bush, "Moses! Moses!" He answered, "Here I am.".