Moses was keeping the flock of his father-in-law Jethro in the wilderness of Midian. He led the flock beyond the wilderness and came to Horeb, the mountain of God. There the angel of the Lord appeared to him in a flame of fire out of a bush; and Moses looked, and the bush was burning, yet it was not consumed.
When Moses turned aside to see, God called to him out of the bush: 'Moses, Moses!' He said, 'Here I am.' Then God said, 'Come no closer! Remove the sandals from your feet, for the place on which you are standing is holy ground' (Exodus 3:4–5). God revealed Himself as the God of Abraham, Isaac, and Jacob, and announced His intention to deliver Israel from Egypt. When Moses asked His name, He answered: 'I AM WHO I AM' — the eternal Being itself.
Christian tradition has venerated the site at the foot of Mount Sinai (Jebel Musa) since at least the 4th century; the Byzantine Emperor Justinian built St. Catherine's Monastery there between 548 and 565 — the world's oldest continuously inhabited Christian monastery. A descendant of the original bramble is still cultivated in the monastery courtyard, and a silver star beneath the chapel altar marks the traditional spot.