Narrated 'Amr b. Shu'aib:

On his father's authority, said that his grandfather told that a A man came to the Prophet ﷺ crying for help. He said: His slave-girl, Messenger of Allah! He said: Woe to you, what happened with you ? He said that it was an evil one. He saw the slave-girl of his master; he became jealous of him, and cut off his penis. The Messenger of Allah ﷺ said: Bring the man to me. The man was called, but people could not get control over him. The Messenger of Allah ﷺ then said: Go away, you are free. He asked: Messenger of Allah! upon whom does my help lie? He replied: On every believer, or he said: On every Muslim.

Abu Dawud said: The name of the man who was emancipated was Rawh b. Dinar

Abu Dawud said: The man who cut off the penis was Zinba'

Abu Dawud said: The Zinba' Abu Rawh was master of the slave.

حَدَّثَنَا مُحَمَّدُ بْنُ الْحَسَنِ بْنِ تَسْنِيمٍ الْعَتَكِيُّ، حَدَّثَنَا مُحَمَّدُ بْنُ بَكْرٍ، أَخْبَرَنَا سَوَّارٌ أَبُو حَمْزَةَ، حَدَّثَنَا عَمْرُو بْنُ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، قَالَ جَاءَ رَجُلٌ مُسْتَصْرِخٌ إِلَى النَّبِيِّ ﷺ فَقَالَ جَارِيَةٌ لَهُ يَا رَسُولَ اللَّهِ . فَقَالَ " وَيْحَكَ مَا لَكَ " . قَالَ شَرًّا أَبْصَرَ لِسَيِّدِهِ جَارِيَةً لَهُ فَغَارَ فَجَبَّ مَذَاكِيرَهُ . فَقَالَ رَسُولُ اللَّهِ ﷺ " عَلَىَّ بِالرَّجُلِ " . فَطُلِبَ فَلَمْ يُقْدَرْ عَلَيْهِ فَقَالَ رَسُولُ اللَّهِ ﷺ " اذْهَبْ فَأَنْتَ حُرٌّ " . فَقَالَ يَا رَسُولَ اللَّهِ عَلَى مَنْ نُصْرَتِي قَالَ " عَلَى كُلِّ مُؤْمِنٍ " . أَوْ قَالَ " كُلِّ مُسْلِمٍ " . قَالَ أَبُو دَاوُدَ الَّذِي عُتِقَ كَانَ اسْمُهُ رَوْحُ بْنُ دِينَارٍ . قَالَ أَبُو دَاوُدَ الَّذِي جَبَّهُ زِنْبَاعٌ . قَالَ أَبُو دَاوُدَ هَذَا زِنْبَاعٌ أَبُو رَوْحٍ كَانَ مَوْلَى الْعَبْدِ .