Sahih Muslim Book 20, Hadith Number 4492.

Chapter : Undesirability of getting a position of authority without necessity.

It has been reported on the authority of Abu Dharr that the Messenger of of Allah (may peace be upon him) said: Abu Dharr, I find that thou art weak and I like for thee what I like for myself. Do not rule over (even) two persons and do not manage the property of an orphan.