Sahih Muslim Book 020, Hadith Number 4493.
Chapter : The merits of a just ruler and the demerits of a tyrant ruler.
It has been narrated on the authority of 'Abdullah b. 'Umar that the Messenger of Allah (may peace be upon him) said: Behold! the Dispensers of justice will be seated on the pulpits of light beside God, on the right side of the Merciful, Exalted and Glorious. Either side of the being is the right side both being equally meritorious. (The Dispensers of justice are) those who do justice in their rules, in matters relating to their families and in all that they undertake to do.