Rashi on Numbers 31:14/רש"י על במדבר ל״א:י״ד

1ויקצף משה על פקודי החיל AND MOSES WAS ANGRY WITH THE פקודי החיל — WITH THOSE APPOINTED OVER THE ARMY — This serves to teach you that every misdeed of a generation is attributed to the leaders since these have the power to protest (Sifrei Bamidbar 157:5).