I met Abu Ztharr at Ar-Rabzthah wearing a garment, and his slave was wearing a [similar] one. So I asked him about that and he mentioned that he had insulted a man during the time of the Messenger of Allah (PBUH), by making a [racist] remark about his mother. The man went to the Prophet (PBUH) and mentioned that to him. So the Prophet (PBUH) said to Abu Ztharr: You are a man who has remnants of pre-Islamic times of ignorance. Your slaves are your brothers upon whom Allah has given you authority. So whoever has his brother under his authority, let him feed him from what he eats and clothe him from what he wears, and do not overburden them with what they cannot bear. But if you burden them, then help them with it.