Sunan Ibn Majah, Book 19, Hadith 2621 (In-Book) ⓘ
It was narrated from Ibn`Umar that the Messenger of Allah said: “Whoever becomes the master of a Mahram relative, he becomes free.”
حَدَّثَنَا رَاشِدُ بْنُ سَعِيدٍ الرَّمْلِيُّ، وَعُبَيْدُ اللَّهِ بْنُ الْجَهْمِ الأَنْمَاطِيُّ، قَالاَ حَدَّثَنَا ضَمْرَةُ بْنُ رَبِيعَةَ، عَنْ سُفْيَانَ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ مَلَكَ ذَا رَحِمٍ مَحْرَمٍ فَهُوَ حُرٌّ " .
also referenced under: Hadith 2525 (Reference) & Volume 3, Book 19, Hadith 2525 (DarusSalam)