Sahih Muslim
The Book on Government (Kitab Al-Imara)
Book Number: 020 / Hadith Number: 4487
It has been reported on the authority of 'Abd al-Rahman b. Samura who said: The Messenger of Allah (may peace be upon him) said to me: 'Abd al-Rahman, do not ask for a position of authority, for if you are granted this position as a result of your asking for it, you will be left alone (without God's help to discharge the responsibilities attendant thereon), and it you are granted it without making any request for it, you will be helped (by God in the discharge of your duties).