Charles Ellicott Commentary Exodus 19:2

"And when they were departed from Rephidim, and were come to the wilderness of Sinai, they encamped in the wilderness; and there Israel encamped before the mount." — Exodus 19:2 (ASV)

They were departed from Rephidim. —If Rephidim was where we have placed it, in the Wady Feiran, the march to “the wilderness of Sinai” (Er Rahah) must have been by the Wady Solaf, or the Wady esh Sheikh, or possibly by both. The distance by Wady Solaf is about eighteen; by Wady esh Sheikh about twenty-five miles. The wilderness of Sinai, now generally identified with Er Rahah, is a plain two miles long by half a mile wide, “enclosed between two precipitous mountain ranges of black and yellow granite, and having at its end the prodigious mountain block of Ras Sufsafeh” (Stanley, Sinai and Palestine, p. 74). It is nearly flat, and covered at present with stunted tamarisk bushes. “No spot in the whole peninsula is so well supplied with water” (Our Work in Palestine, p. 268).

Israel camped before the mount. —On the capacity of the plain Er Rahah to receive the entire multitude, see Stanley (Sinai and Palestine, p. 42), and compare the comment on Exodus 12:37-41. The Ras Sufsafeh is visible from every part of the plain.