All the congregation of the people of Israel is the same expression used in 16.1 (see the discussion there). Moved on, literally “they pulled up stakes,” means they broke camp and “set out” (Revised English Bible). (See 12.37.) For wilderness of Sin see the comment at 16.1. By stages is literally “to [or, according to] their setting out.” This refers to the various places where they stopped along their journey, so Good News Translation has “moving from one place to another,” and New International Version has “traveling from place to place.” (The same word is used in Num 33.1-2.)

According to the commandment of the LORD is literally “upon the mouth of Yahweh.” Other ways to express this are “at the command of the LORD,” or even “each time the LORD ordered them to” (Contemporary English Version). And camped at Rephidim identifies the place where this episode took place. They had, of course, camped at other places along the way, since they had moved by stages. Rephidim cannot be located with certainty, but 19.1 places it not far from Mount Sinai. It was probably a wilderness oasis or stopping place where water was usually found. Another way to translate this clause is “Finally they came to [a place called] Rephidim.” But there was no water for the people to drink explains why the people again complained, but there is no indication as to why there was no water. Since the text adds for the people to drink, we should allow for the possibility that there may indeed have been water there, but that the Israelites were denied access to it for some reason not mentioned. It may have been controlled at that time by the Amalekites, who fought with them there (verse 8).

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .