Arabic (Original)
حَدَّثَنَا وَكِيعٌ عَنْ سُفْيَانَ عَنْ فِرَاسٍ عَنْ أَبِي صَالِحٍ عَنْ زَاذَانَ أَنَّ ابْنَ عُمَرَ أَعْتَقَ عَبْدًا لَهُ فَقَالَ مَا لِي مِنْ أَجْرِهِ وَتَنَاوَلَ شَيْئًا مِنْ الْأَرْضِ مَا يَزِنُ هَذِهِ أَوْ مِثْلَ هَذِهِ سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ مَنْ لَطَمَ غُلَامَهُ أَوْ ضَرَبَهُ فَكَفَّارَتُهُ عِتْقُهُ.
English Translation
Waki' narrated to us, from Sufyan, from Firas, from Abu Salih, from Zadhan, that Ibn 'Umar freed a slave of his, then said: 'What reward do I have from this?' And he picked up something from the ground - 'not even the weight of this,' or 'the like of this.' I heard the Messenger of Allah, peace and blessings be upon him, say: 'Whoever slaps his servant boy or strikes him, his atonement is to free him.'