Messenger of Allah (ﷺ) said, "Whosoever among you is appointed by us to a position and he conceals from us even a needle or less, it will amount to misappropriation and he will be called upon to restore it on the Day of Resurrection". ('Adi bin 'Umairah added:) A black man from the Ansar stood up - I can see him still - and said: "O Messenger of Allah, take back from me your assignment." He (the Prophet (ﷺ)) said, "What has happened to you?" The man replied: "I have heard you saying such and such." He (ﷺ) said, "I say that even now: Whosoever from you is appointed by us to a position, he should render an account of everything, big or small, and whatever he is given therefrom, he should take and he should desist from taking what is unlawful".

[Muslim].