Abu'd-Darda' used to say to people. "We know you better than the veterinarian knows his animals. We recognise the best of you from the worst of you. The best of you is the one whose good is hoped for and the one whose evil you are safe from. As for the worst of you, that is the person whose good is not hoped for and whose evil you are not safe from and he does not free slaves."  

أَنَّهُ كَانَ يَقُولُ لِلنَّاسِ نَحْنُ أَعْرَفُ بِكُمْ مِنَ الْبَيَاطِرَةِ بِالدَّوَابِّ قَدْ عَرَفْنَا خِيَارَكُمْ مِنْ شِرَارِكُمْ أَمَّا خِيَارُكُمُ الَّذِي يُرْجَى خَيْرُهُ وَيُؤْمَنُ شَرُّهُ وَأَمَّا شِرَارُكُمْ فَالَّذِي لاَ يُرْجَى خَيْرُهُ وَلاَ يُؤْمَنُ شَرُّهُ وَلاَ يُعْتَقُ مُحَرَّرُهُ  

Abu Umama said, "Ingratitude is typified by someone who refuses to give, lives alone, and beats his slave."  

الْكَنُودُ الَّذِي يَمْنَعُ رِفْدَهُ وَيَنْزِلُ وَحْدَهُ وَيَضْرِبُ عَبْدَهُ  

Al-Hasan reported that a man ordered one of his slaves to draw water using one of his camels and the man fell asleep. The master came with a torch and put it in his face and the slave fell into the well. In the morning, the slave went to 'Umar ibn al-Khattab and 'Umar saw what had happened to his slave and therefore 'Umar set him free."  

أَنَّ رَجُلاً أَمَرَ غُلاَمًا لَهُ أَنْ يَسْنُوَ عَلَى بَعِيرٍ لَهُ فَنَامَ الْغُلاَمُ فَجَاءَ بِشُعْلَةٍ مِنْ نَارٍ فَأَلْقَاهَا فِي وَجْهِهِ فَتَرَدَّى الْغُلاَمُ فِي بِئْرٍ فَلَمَّا أَصْبَحَ أَتَى عُمَرَ بْنَ الْخَطَّابِ رَضِيَ اللَّهُ عَنْهُ فَرَأَى الَّذِي فِي وَجْهِهِ فَأَعْتَقَهُ