Exodus 3:2-6

2 And the angel of the LORD appeared to him in a flame of fire out of the middle of a bush: and he looked, and, behold, the bush burned with fire, and the bush was not consumed.

3 And Moses said, I will now turn aside, and see this great sight, why the bush is not burnt.

4 And when the LORD saw that he turned aside to see, God called to him out of the middle of the bush, and said, Moses, Moses. And he said, Here am I.

5 And he said, Draw not near here: put off your shoes from off your feet, for the place where on you stand is holy ground.

6 Moreover he said, I am the God of your father, the God of Abraham, the God of Isaac, and the God of Jacob. And Moses hid his face; for he was afraid to look on God.