'The mountain of God' (Exodus 3:1), where the bush burns, where Moses is called, and where — one book later — Israel will camp for a year and receive the Law in fire and cloud. HOREB and SINAI are the same mountain under two names (Exodus tends to 'Sinai,' Deuteronomy to 'Horeb'); the exact peak is unknown. The traditional site since Byzantine times is JEBEL MUSA ('the mountain of Moses') in the south-central Sinai Peninsula, at whose foot St. Catherine's Monastery guards a thornbush said to be the descendant of the seneh. Other proposals have been argued — a northern Sinai peak, or JEBEL AL-LAWZ in northwest Arabia (favored by those who place Midian, where Moses was shepherding, across the Gulf of Aqaba, and read Galatians 4:25's 'Sinai in Arabia' literally) — none decisive. What the text fixes is not the coordinates but the pattern: the God who meets Moses here in fire brings the whole nation back to the same fire (Exodus 19), and the sign given at the bush is the meeting itself — 'you will serve God on this mountain' (3:12).