Sahih Muslim Book 20, Hadith Number 4560.

Chapter : Instruction to stick to the main body of the Muslims in the time of trials and warning against those inviting people to disbelief.

It has been narrated (through a different chain of transmitters) on the authority of Ibn Abbas that the Messenger of Allah (may peace be upon him) said: One who dislikes a thing done by his Amir should be patient over it, for anyone from the people who withdraws (his obedience) from the government, even to the extent of a hand-span and died in that conditions, would die the death of one belonging to the days of jahilliyya.