Why does the Torah add the word "l'Mas'eihem"?
Ramban: Because they traveled from Midbar Sin to Refidim via Dofkah and Alush (where the episode with the Manna took place). 1
Ramban: The Torah omits these two stops here, because it is only concerned with the places where they grumbled - in Alush (at the beginning of Desert Sin) they grumbled about the lack of bread; and now, when they arrived in Refidim, about the lack of water.
What exactly happened here? What were they grumbling about?
Ramban and Targum Yonasan: They arrived at Refidim and did not find water (because the local water-springs had dried up - Targum Yonasan).
Why did Hashem leave them without water?
Targum Yonasan: Because they were lax in the Mitzvos that they had already been commanded (at Marah?). 1
Which explains why the place was called 'Refidim', which is the acronym of "Rafu Yedeihem (mi'Divrei Torah)." See Torah Temimah, citing Sanhedrin 106a, and note 1, where he elaborates.
Chazal discuss the name "Refidim" (Sanhedrin 106a); according to Rebbi Eliezer this was simply its name, whereas according to Rebbi Yehoshua it indicates that Bnei Yisrael were slacking (Ripu Atzman) in learning Torah." What conceptually is behind this dispute?
Maharal (Chidushei Agados Vol. 3, p. 248, to Sanhedrin 106a): According to Rebbi Eliezer, a person is by nature inclined towards sin, due to his physical Guf. But according to Rebbi Yehoshua, one only falls towards sin if he turns away from Torah-learning. 1
Maharal similarly explains the Gemara's following discussion (loc. cit.) - Was "Shitim" simply a location (of the sin with Benos Moav, Bamidbar 25), or does its name indicate an act of Shetus (folly - in that they ate of their sacrifices beforehand)? Whereas that sin was in the Guf, the sin here at Refidim was in the Sechel (the mind) - they challenged Hashem as to whether His Presence was among them (17:7). In either case, according to R' Eliezer, we need not explain why man is prone to sin; whereas according to R' Yehoshua, each sin was brought about by a specific short-falling in that same sphere. In this case, they failed to use their minds to learn Torah, and that led to their doubting of Hashem's Providence in their minds.
