The Book on Government (Kitab Al-Imara)
Muslim :: Book 20 : Hadith 4491
It has been narrated on the authority of Abu Dharr who said: I said to the Holy Prophet (may peace be upon him): Messenger of Allah, will you not appoint me to a public office? He stroked my shoulder with his hand and said: Abu Dharr, thou art weak and authority is a trust. and on the Day of judgment it is a cause of humiliation and repentance except for one who fulfils its obligations and (properly) discharges the duties attendant thereon.