حَدَّثَنَا مُوسَى، قَالَ: حَدَّثَنَا أَبُو عَوَانَةَ، قَالَ: حَدَّثَنَا فِرَاسٌ، عَنْ أَبِي صَالِحٍ، عَنْ زَاذَانَ أَبِي عُمَرَ قَالَ: كُنَّا عِنْدَ ابْنِ عُمَرَ، فَدَعَا بِغُلاَمٍ لَهُ كَانَ ضَرَبَهُ فَكَشَفَ عَنْ ظَهْرِهِ فَقَالَ: أَيُوجِعُكَ؟ قَالَ: لاَ. فَأَعْتَقَهُ، ثُمَّ رَفَعَ عُودًا مِنَ الأَرْضِ فَقَالَ: مَالِي فِيهِ مِنَ الأَجْرِ مَا يَزِنُ هَذَا الْعُودَ، فَقُلْتُ: يَا أَبَا عَبْدِ الرَّحْمَنِ، لِمَ تَقُولُ هَذَا؟ قَالَ: سَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَقُولُ أَوْ قَالَ: مَنْ ضَرَبَ مَمْلُوكَهُ حَدًّا لَمْ يَأْتِهِ، أَوْ لَطَمَ وَجْهَهُ، فَكَفَّارَتُهُ أَنْ يُعْتِقَهُ.
Abu 'Umar Zadhan said, "We were with Ibn 'Umar when he summoned a slave of his whom he had beaten and he uncovered his back. 'Does it hurt?' he asked. 'No,' he replied. Then he set him free. He picked up a stick from the ground and then said, 'I do not have a reward (for him) worth as much as this stick.' I asked, 'Abu 'Abdu'r-Rahman, why do you say this?' He replied, 'I heard the Prophet, may Allah bless him and grant him peace, say, "The expiation of someone who beats a slave more than he deserves or slaps his face is that he must set him free."'"
Cited in Al-Adab al-Mufrad (No. 180).