Or HaChaim on Exodus 15:24/אור החיים על שמות ט״ו:כ״ד

1 וילונו העם על משה, The people murmured against Moses, etc. The Torah criticises the manner in which the people provoked a quarrel. The Torah does not deny the validity of a people asking for drinkable water, i.e. the question: "what are we to drink?" They should have asked for their needs in an appropriate manner.