Ammianus Marcellinus Res Gestae 16.11.12

[12] And not content with that alone, he gathered for himself also rations to serve for twenty days. For the warriors the more willingly made use of what they had won by their own right hands, being greatly incensed because from the supplies which had just been brought them they could get nothing, since Barbatio had arrogantly appropriated a part of them, when they were passing near him; and piled in a heap what remained over and burned it. Whether he did this like an empty-headed fool, or at the emperor’s bidding brazenly perpetrated his many abominable acts, has remained obscure up to this time.