Sahih Bukhari Volume 3, Book 49, Hadith 2546

حَدَّثَنَا آدَمُ بْنُ أَبِي إِيَاسٍ، حَدَّثَنَا شُعْبَةُ، حَدَّثَنَا وَاصِلٌ الأَحْدَبُ، قَالَ سَمِعْتُ الْمَعْرُورَ بْنَ سُوَيْدٍ، قَالَ رَأَيْتُ أَبَا ذَرٍّ الْغِفَارِيَّ ـ رضى الله عنه ـ وَعَلَيْهِ حُلَّةٌ وَعَلَى غُلاَمِهِ حُلَّةٌ فَسَأَلْنَاهُ عَنْ ذَلِكَ فَقَالَ إِنِّي سَابَبْتُ رَجُلاً فَشَكَانِي إِلَى النَّبِيِّ صلى الله عليه وسلم، فَقَالَ لِيَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ أَعَيَّرْتَهُ بِأُمِّهِ ‏"‏‏.‏ ثُمَّ قَالَ ‏"‏ إِنَّ إِخْوَانَكُمْ خَوَلُكُمْ جَعَلَهُمُ اللَّهُ تَحْتَ أَيْدِيكُمْ، فَمَنْ كَانَ أَخُوهُ تَحْتَ يَدِهِ فَلْيُطْعِمْهُ مِمَّا يَأْكُلُ، وَلْيُلْبِسْهُ مِمَّا يَلْبَسُ، وَلاَ تُكَلِّفُوهُمْ مَا يَغْلِبُهُمْ، فَإِنْ كَلَّفْتُمُوهُمْ مَا يَغْلِبُهُمْ فَأَعِينُوهُمْ ‏"‏‏.‏

Narrated By Al-Ma'rur bin Suwaid : 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. The Prophet 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)."