Sahih Muslim
The Book on Government (Kitab Al-Imara)
Book Number: 020 / Hadith Number: 4693
It has been narrated through a different chain of transmitters on the authority of Sufyan who said that he heard 'Umar b. al-Khattab relate (this tradition) from the Holy Prophet (may peace be upon him) while he was delivering a sermon from the pulpit.