וְלֹא־הָ֥יָה מַ֖יִם לָעֵדָ֑ה וַיִּקָּ֣הֲל֔וּ עַל־מֹשֶׁ֖ה וְעַֽל־אַהֲרֹֽן׃
And there was no water for the congregation; and they assembled themselves together against Moses and against Aaron.
Rashi on Numbers
ולא היה מים לעדה AND THERE WAS NO WATER FOR THE CONGREGATION — Since this statement follows immediately after the mention of Miriam’s death, we may learn from it that during the entire forty years they had the “well” through Miriam’s merit (Taanit 9a).
Tur HaArokh
-3. ויקהלו העם על משה ועל אהרן וירב העם עם משה, “The people gathered against Moses and Aaron and they quarreled with Moses.” Although they gathered against both Moses and Aaron, their principal target was Moses with whom they started quarrelling.