Umm Salamah relates that the Holy Prophet said: I am but a human being. You bring your disputes to me for decision. It might happen that one party might be better versed in presenting his case than the other and I might decide in his favor according to what I hear. But, if I decide in favor of one contrary to the right of the other, I merely allot a brand of fire to him. (Bokhari and Muslim)
Note: We are quoting from the book Gardens of Righteous, chapter 26.