Albert Barnes Commentary Exodus 15:22

"And Moses led Israel onward from the Red Sea, and they went out into the wilderness of Shur; and they went three days in the wilderness, and found no water." — Exodus 15:22 (ASV)

So Moses – Literally, And Moses. The history of the journey from the Red Sea to Sinai begins in fact with this verse, which would more conveniently have been the commencement of another chapter.

From the Red sea – The station where Moses and his people halted to celebrate their deliverance is generally admitted to be Ayoun Musa, i.e., the fountains of Moses. It is the only green spot near the passage over the Red Sea. There are several wells there, which in the time of Moses were probably enclosed and kept with great care by the Egyptians, for the use of the frequent convoys to and from their ancient settlements at Sarbutel Khadem and the Wady Mughara.

The wilderness of Shur – This name belongs to the whole district between the northeastern frontier of Egypt and Palestine. The word is undoubtedly Egyptian and is probably derived from the word Khar, which designated all the country between Egypt and Syria proper.

Three days – The distance between Ayoun Musa and Huwara, the first spot where any water is found on the route, Isaiah 33 geographical miles. The whole district is a tract of sand or rough gravel.