Rav Hirsch on Beshalach 15:24
וַיִּלֹּנוּ הָעָם עַל משֶׁה לֵּאמֹר מַה נִּשְׁתֶּה
:tranlates this as
And the people murmured against Moshe, saying: What shall we drink?
וילונו - לון
to seek shelter from hardship, hence to stay somewhere overnight, and
מלון an inn. From which we get הלון על to seek redress from a
hardship which one has to endure, to put yourself above somebody, to
speak and spread abroad complaints about somebody, to grumble about
Here they not only had no water but they had undrinkable water. They did not realize that had they gotten to a real oasis, there would have been people there who would have objected to their coming. However, Hashem had set up a situation where He would sweeten the water for them, but the population of the area knew that the water was undrinkable (as shown by the name) and had abandoned it. Had they encountered people they would have panicked and run.
Rav Hirsch then translates Beshalach 17::2
וַיָּרֶב הָעָם עִם משֶׁה וַיֹּאמְרוּ תְּנוּ לָנוּ מַיִם וְנִשְׁתֶּה
וַיֹּאמֶר לָהֶם משֶׁה מַה תְּרִיבוּן עִמָּדִי מַה תְּנַסּוּן אֶת
And the people contended with Moshe and said: Give us water that we may
Rav Hirsch comments:
וירב is not תלונה as in verse 3, which we found (from the meaning of
לון) to mean seeking relief from some privation or distress that one
is beginning to feel, but וירב is chiefly used for establishing a
supposed or real claim to something to which one has a right, as in
the dispute over the wells (Gen. XXVI,20). Here they were not yet
making any reproaches, did not refer to their requirements, but as a
justified claim, demanded water. Where we camp, there must be water:
תנו לנו מים As the ן in תריבון and תנוסון stresses the second person, the retort runs: you know quite well that it is not I but
Hashem who has led you hither, and surely you have by now had
sufficient experience of Hashem to quietly trust to Him that here also
He will not let you die of thirst. In ordinary circumstances your
demand would be quite justified, but you etc.
Note that Beshalach 17:3
וַיִּצְמָא שָׁם הָעָם לַמַּיִם וַיָּלֶן הָעָם עַל משֶׁה וַיֹּאמֶר
לָמָּה זֶּה הֶעֱלִיתָנוּ מִמִּצְרַיִם לְהָמִית אֹתִי וְאֶת בָּנַי
וְאֶת מִקְנַי בַּצָּמָא:
Rav Hirsch translates as
But when the people thirsted ...
Rav Hirsch points out that they still had water and manufactured an argument because new water was not waiting for them. Had they waited one more station, they would have arrived at Chorev and received the miraculous well of Miriam that was to provide them with water for the entire trip. Thus, the Torah uses the term for argument rather than recognition of a justified complaint.