Albert Barnes Commentary Exodus 17:1

"And all the congregation of the children of Israel journeyed from the wilderness of Sin, by their journeys, according to the commandment of Jehovah, and encamped in Rephidim: and there was no water for the people to drink." — Exodus 17:1 (ASV)

According to their journeys - The Israelites rested at two stations before they reached Rephidim, namely, Dophkah and Alush (Numbers 33:12–14). Dophkah was in the Wady Sih, a day’s journey from the Wady Nasb.

The wilderness of Sin (Exodus 16:1) properly speaking ends here; the sandstone ceases, and is replaced by the porphyry and granite which belong to the central formation of the Sinaitic group. Alush may have been near the entrance to the Wady Sheikh.

Rephidim - (Variously placed at Feiran at the base of Mount Serbal, or at the pass of El Watiyeh.)