Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
bayhaqi:13732ʿAlī b. Muḥammad b. ʿAbdullāh b. Bishrān > Ismāʿīl b. Muḥammad al-Ṣaffār > al-Ḥasan b. ʿAlī b. ʿAffān > ʿAbdullāh b. Numayr > ʿAbdullāh b. ʿUmar > Nāfiʿ > Ibn ʿUmar

[Machine] That the marriage of a slave without the permission of their master is considered adultery and those who marry them will be punished.  

البيهقي:١٣٧٣٢أَخْبَرَنَا عَلِيُّ بْنُ مُحَمَّدِ بْنِ عَبْدِ اللهِ بْنِ بِشْرَانَ أنبأ إِسْمَاعِيلُ بْنُ مُحَمَّدٍ الصَّفَّارُ ثنا الْحَسَنُ بْنُ عَلِيِّ بْنِ عَفَّانَ ثنا عَبْدُ اللهِ بْنُ نُمَيْرٍ عَنْ عَبْدِ اللهِ بْنِ عُمَرَ عَنْ نَافِعٍ عَنِ ابْنِ عُمَرَ أَنَّهُ كَانَ يَرَى

أَنَّ نِكَاحَ الْعَبْدِ بِغَيْرِ إِذْنِ سَيِّدِهِ زِنًا وَيُعَاقَبُ مَنْ زَوَّجَهُ