(45) باب قَذْفِ الْعَبِيدِ
Narrated Abu Huraira:
I heard Abu-l-Qasim (the Prophet) saying, "If somebody slanders his slave and the slave is free from what he says, he will be flogged on the Day of Resurrection unless the slave is really as he has described him."
Reference: Sahih al-Bukhari 6858
In-book reference: Book 86, Hadith 81
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 82, Hadith 841