They journeyed from Elim, and all the congregation came. It has been noted (Cook) that the form of expression seems to imply that the Israelites proceeded in detachments from Elim, and were first assembled as a complete host when they reached the wilderness of Sin."
This accords well with their numbers and with the character of the localities. They could only assemble all together when they reached some considerable plain. Between Elim and Sinai. This expression must be regarded as vague to some extent.
On the direct line, as the crow flies, there is no "wilderness" (midbar) between Wady Ghurundel and Sinai. All is mountain and valley. All that the writer means is that "the wilderness of Sin" lay upon the ordinary, or at any rate an ordinary route between Elim and the great mountain.
This is equally true of El Markha and the Debbet-er-Ramleh. On the fifteenth day of the second month—i.e; on the 15th of Zif, exactly one month after their departure from Egypt. As only seven camping places are mentioned (Numbers 33:5-11), and one journey of three days through a wilderness (Exodus 15:22), it is evident that there must either have been long stays in several places, or that they must have often encamped in places which had no name.
Viewed as an itinerary, the record is manifestly incomplete.