Sayyidina Abu Hurayrah reported that Allah’s Messenger (SAW) said, “If a ruler endeavours to be just when giving a command and emerges correct then he gets a dual reward (one for securing the due of the owner of right and the other for his endeavour). But if he does not emerge correct then he gets (just) one reward (nevertheless).”
[Bukhari 7352, Muslim 1716, Abu Dawud 3574, Ibn e Majah 2314, Ahmed 17789]