Exodus 3:1-2
3:1 Now Moses was shepherding the flock of his father-in-law Jethro, the priest of Midian, and he led the flock to the far side of the desert and came to the mountain of God, to Horeb.
3:2 The angel of the Lord appeared to him in a flame of fire from within a bush. He looked – and the bush was ablaze with fire, but it was not being consumed!