Exodus 3:1-2

1 Now Moses was keeping the flock of Jethro, his father-in-law, the priest of Midian, and he led the flock to the back of the wilderness, and came to God's mountain, to Horeb.  2 The angel of Yahweh appeared to him in a flame of fire out of the midst of a bush. He looked, and behold, the bush burned with fire, and the bush was not consumed.