I saw Abu Dhar Al-Ghifari wearing a cloak, and his slave, too, was wearing a cloak. We asked him
about that (i.e. how both were wearing similar cloaks). He replied, "Once I abused a man and he
complained of me to the Prophet (ﷺ) . The Prophet (ﷺ) asked me, 'Did you abuse him by slighting his
mother?' He added, 'Your slaves are your brethren upon whom Allah has given you authority. So, if
one has one's brethren under one's control, one should feed them with the like of what one eats and
clothe them with the like of what one wears. You should not overburden them with what they cannot
bear, and if you do so, help them (in their hard job).
Sahih al-Bukhari Book 49, Hadith 28