Sahih Bukhari Volume 001, Book 002,
Hadith Number 029.
Sahih Bukhari Book 02. Belief
Narated By Al-Ma'rur : At Ar-Rabadha
I met Abu Dhar who was wearing a
cloak, and his slave, too, was wearing
a similar one. I asked about the
reason for it. He replied, "I abused a
person by calling his mother with bad
names." The Prophet said to me, 'O
Abu Dhar! Did you abuse him by
calling his mother with bad names
You still have some characteristics of
ignorance. Your slaves are your
brothers and Allah has put them
under your command. So whoever
has a brother under his command
should feed him of what he eats and
dress him of what he wears. Do not
ask them (slaves) to do things beyond
their capacity (power) and if you do
so, then help them.'"