Exodus 19:2 For they were departed from Rephidim, and were come to the desert of Sinai, and had pitched in the wilderness; and there Israel camped before the mount. - Free Bible Online

      2. were come to the desert of Sinai--The desert has its provinces, or divisions, distinguished by a variety of names; and the "desert of Sinai" is that wild and desolate region which occupies the very center of the peninsula, comprising the lofty range to which the mount of God belongs. It is a wilderness of shaggy rocks of porphyry and red granite, and of valleys for the most part bare of verdure.
      and there Israel camped before the mount--Sinai, so called from Seneh, or acacia bush. It is now called Jebel Musa. Their way into the interior of the gigantic cluster was by Wady Feiran, which would lead the bulk of the hosts with their flocks and herds into the high valleys of Jebel Musa, with their abundant springs, especially into the great thoroughfare of the desert--the longest, widest, and most continuous of all the valleys, the Wady-es-Sheikh, while many would be scattered among the adjacent valleys; so that thus secluded from the world in a wild and sublime amphitheatre of rocks, they "camped before the mount." "In this valley--a long flat valley--about a quarter of a mile in breadth, winding northwards, Israel would find ample room for their encampment. Of all the wadys in that region, it seems the most suitable for a prolonged sojourn. The 'goodly tents' of Israel could spread themselves without limit" [BONAR].

JFB.