حَدَّثَنَا عُقْبَةُ بْنُ مُكْرَمٍ، حَدَّثَنَا أَبُو قُتَيْبَةَ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ ‏"‏ إِذَا نَكَحَ الْعَبْدُ بِغَيْرِ إِذْنِ مَوْلاَهُ فَنِكَاحُهُ بَاطِلٌ ‏"‏ ‏.‏ قَالَ أَبُو دَاوُدَ هَذَا الْحَدِيثُ ضَعِيفٌ وَهُوَ مَوْقُوفٌ وَهُوَ قَوْلُ ابْنِ عُمَرَ رضى الله عنهما ‏.‏

Ibn ‘Umar reported the Prophet (PBUH) as saying “If a slave marries without the permission of his master, his marriage is null and void. Abu Dawud said “This tradition is weak. This is mauquf(does not go back to the Prophet). This is the statement of the Ibn ‘Umar himself. Translation Not Available

Book Ref: Sunan Abi Dawud Book 12 Hadith 2079
Web Ref:  Sunan Abi Dawud Book 11 Hadith 2074