Sahih Bukhari
Judgments (Ahkaam)
Volume: 009 / Book Number: 089 / Hadith Number: 292
Narrated Um Salama:
(the wife of the Prophet) Allah's Apostle heard some people quarreling 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 favor. If ever I pass a judgment in favor 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."