I was beating my slave with a whip when I heard a voice behind me: Understand, Abu Masud; but I did not recognise the voice due to intense anger. He (Abu Mas'ud) reported: As he came near me (I found) that he was the Messenger of Allah ﷺ and he was saying: Bear in mind, Abu Mas'ud; bear in mind. Abu Mas'ud. He (Aba Maslad) said: threw the whip from my hand. Thereupon he (the Holy Prophet) said: Bear in mind, Abu Mas'ud; verily Allah has more dominance upon you than you have upon your slave. I (then) said: I would never beat my servant in future.  

أَبُو مَسْعُودٍ الْبَدْرِيُّ كُنْتُ أَضْرِبُ غُلاَمًا لِي بِالسَّوْطِ فَسَمِعْتُ صَوْتًا مِنْ خَلْفِي اعْلَمْ أَبَا مَسْعُودٍ فَلَمْ أَفْهَمِ الصَّوْتَ مِنَ الْغَضَبِ قَالَ فَلَمَّا دَنَا مِنِّي إِذَا هُوَ رَسُولُ اللَّهِ ﷺ فَإِذَا هُوَ يَقُولُ اعْلَمْ أَبَا مَسْعُودٍ اعْلَمْ أَبَا مَسْعُودٍ قَالَ فَأَلْقَيْتُ السَّوْطَ مِنْ يَدِي فَقَالَ اعْلَمْ أَبَا مَسْعُودٍ أَنَّ اللَّهَ أَقْدَرُ عَلَيْكَ مِنْكَ عَلَى هَذَا الْغُلاَمِ قَالَ فَقُلْتُ لاَ أَضْرِبُ مَمْلُوكًا بَعْدَهُ أَبَدًا  

[Machine] While I was whipping a young boy, I heard a voice from behind me saying, "Know, Aba Mas'ood." I became so angry that I could not think straight until the Messenger of Allah ﷺ came close to me. When I saw him, the whip fell from my hand and he said, "Know, Aba Mas'ood, that Allah is more capable of punishing you than you are of punishing him." I said, "By the One who sent you with the truth, I will never strike a slave again."  

بَيْنَمَا أَنَا أَضْرِبُ غُلَامًا لِي بِالسَّوْطِ إِذْ سَمِعْتُ صَوْتًا مِنْ خَلْفِي «اعْلَمْ أَبَا مَسْعُودٍ» فَجَعَلْتُ لَا أَعْقِلُ مِنَ الْغَضَبِ حَتَّى دَنَا مِنِّي رَسُولُ اللهِ ﷺ فَلَمَّا رَأَيْتُهُ وَقَعَ السَّوْطُ مِنْ يَدِي فَقَالَ «اعْلَمْ أَبَا مَسْعُودٍ أَنَّ اللهَ أَقْدَرُ عَلَيْكَ مِنْكَ» فَقُلْتُ وَالَّذِي بَعَثَكَ بِالْحَقِّ لَا أَضْرِبُ عَبْدًا أَبَدًا