Hala-'l Badr (or Hala-'l Bedr, in Arabic: حلا البدر) is a volcano in north western Saudi Arabia situated at 27.25° N, 37.235° E.
A number of scholars, including Charles Beke, Sigmund Freud, and Immanuel Velikovsky, have proposed that the biblical description of devouring fire on Mount Sinai refers to an erupting volcano; this possibility would exclude all the peaks on the Sinai Peninsula and Mount Seir, but would match a number of locations in north western Saudi Arabia, of which Hala-'l Badr is the most prominent.
The equation of Sinai with Hala-'l Badr has been advocated by various scholars and authors, including
- Alois Musil in the early 20th century
- Jean Koenig in 1971
- Colin Humphreys in 2003
Humphreys reports that a volcano in the region erupted in AD 640, but it is not known exactly which volcano this was. Hala-'l Badr has a volcanic explosivity index of at least 2, meaning that it is an explosive volcano capable of producing a plume three miles high.
The area of Madyan in which Hala-'l Badr lies is reputed to have been the site of ancient disasters caused by earthquakes and possibly a volcano (see Thamud and Madyan).