The Book of Manumission of Slaves
31/7. Chapter:
Regarding One Who Acquires A Mahram Relative As A Slave
Sunan Abi Dawud
حَدَّثَنَا مُحَمَّدُ بْنُ سُلَيْمَانَ، حَدَّثَنَا عَبْدُ الْوَهَّابِ، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، عَنِ الْحَسَنِ، قَالَ مَنْ مَلَكَ ذَا رَحِمٍ مَحْرَمٍ فَهُوَ حُرٌّ .
Qatadah reported 'Umar b. al-Khattab (ra) as saying: If anyone gets possession of a relative who is within the prohibited degrees, that person becomes free.
Reference : Sunan Abi Dawud 3951In-book reference : Book 31, Hadith 26English translation : Book 30, Hadith 3940