"Vayilonu ha'Am al Moshe .. ". Seeing as they had no water, what was their sin?
R. Bachye: Hashem was testing Yisrael 1 by causing the sweet water to turn bitter ? to see their reaction ? and they failed ? See answer #2 - Then, by making the water sweet again by throwing bitter wood into it, He strengthened their Bitachon by performing a double miracle (Neis be'Soch Neis'). 2
Da'as Zekenim: They should have consulted Moshe before complaining
QUESTIONS ON RASHI
Rashi writes: "Va'Yilonu - [A verb] in passive form (Nif'al)" (i.e., 'they became complaining'). Why must it be Nif'al?
Gur Aryeh: Had the verb not been in Nif'al form (but rather in Kal), the Yud would have had a Kamatz (va'Yalonu). The Chirik shows that it is Nif'al (as in the Pasuk "Yikonu Yachdav" - Mishlei 22:18). 1
Furthermore, the Dagesh in the letter Lamed of "va'Yilonu," comes in place of the missing Nun of Nif'al. Had it been in Kal form, there would be no Dagesh in the Lamed. (CS)
Rashi writes: "Va'Yilonu - ... The Targum is likewise a Nif'al expression, 'v'is'Ra'amu.' It is common, in expressions of complaint, to direct the expression towards oneself (i.e., a reflexive verb), [for example] 'Mislonein,' 'Misro'eim;' rather than 'Lonen' or 'Ro'eim.'" What is Rashi pointing out here?
Gur Aryeh: Despite that the person complaining is the initiator of the action, and not the recipient, the verb often takes reflexive form (Hispa'el) - something that one does toward onesself. 1
E.g., 'Mislabesh' - he dresses himself, 'Misrachetz' - he washes himself. Also see Ibn Ezra (longer commentary).
