Narrated Abu Huraira (Radi-Allahu 'anhu):
Allah's Apostle (Sallallahu 'Alaihi Wa Sallam) said, "Whoever has oppressed
another person concerning his reputation or anything else, he should beg
him to forgive him before the Day of Resurrection when there will be no
money (to compensate for wrong deeds), but if he has good deeds, those good
deeds will be taken from him according to his oppression which he has done,
and if he has no good deeds, the sins of the oppressed person will be
loaded on him."

Bukhari Vol. 3 : No. 629