(31) The Book of Manumission of Slaves
كتاب العتق
(1489) Chapter: Regarding One Who Acquires A Mahram Relative As A Slave
(7) باب فِيمَنْ مَلَكَ ذَا رَحِمٍ مَحْرَمٍ
Sunan Abi Dawud 3950 

Narrated Umar ibn al-Khattab:

Qatadah reported Umar ibn al-Khattab (may Allah be pleased with him) as saying: If anyone gets possession of a relative who is within the prohibited degrees, that person becomes free.

حَدَّثَنَا مُحَمَّدُ بْنُ سُلَيْمَانَ الأَنْبَارِيُّ، حَدَّثَنَا عَبْدُ الْوَهَّابِ، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، أَنَّ عُمَرَ بْنَ الْخَطَّابِ، - رضى الله عنه - قَالَ مَنْ مَلَكَ ذَا رَحِمٍ مَحْرَمٍ فَهُوَ حُرٌّ ‏.‏
Grade :  Da'if Mauquf (Al-Albani) ضعيف موقوف  (الألباني)حكم :
Reference : Sunan Abi Dawud 3950
In-book reference : Book 31, Hadith 25
English translation : Book 30, Hadith 3939