ENOfficial
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.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُحَمَّدُ بْنُ سُلَيْمَانَ، حَدَّثَنَا عَبْدُ الْوَهَّابِ، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، عَنِ الْحَسَنِ، قَالَ مَنْ مَلَكَ ذَا رَحِمٍ مَحْرَمٍ فَهُوَ حُرٌّ .
sunnah.com