Easton's Bible Dictionary: M. G. Easton, M.A., D.D.
Desert or mountain of the dried-up ground, a general name for the whole mountain range of which Sinai was one of the summits (Ex. 3:1, 17:6, 33:6; Ps. 106:19, etc.). The modern name of the whole range is Jebel Musa. It is a huge mountain block, about 2 miles long by about 1 in breadth, with a very spacious plain at its north-east end, called the Er Rahah, in which the Israelites encamped for nearly a whole year.