Sahih Bukhari | Volume 9 | Hadith Number 292

Narrated by Um Salama
(The wife of the Prophet) Allah's Apostle heard some people quarrelling at the door of his dwelling, so he went out to them and said, "I am only a human being, and litigants with cases of dispute come to me, and someone of you may happen to be more eloquent (in presenting his case) than the other, whereby I may consider that he is truthful and pass a judgment in his favour. If ever I pass a judgment in favour of somebody whereby he takes a Muslim's right unjustly, then whatever he takes is nothing but a piece of Fire, and it is up to him to take or leave."