Exod 3:2-4

2There the angel of the Lord appeared to him in a flame of fire out of a bush; he looked, and the bush was blazing, yet it was not consumed.3Then Moses said, “I must turn aside and look at this great sight, and see why the bush is not burned up.”4When the Lord saw that he had turned aside to see, God called to him out of the bush, “Moses, Moses!” And he said, “Here I am.”