(19) The Chapters on Manumission (of Slaves)
كتاب العتق
(1) Chapter: The Mudabbar
(1.00) باب الْمُدَبَّرِ
Sunan Ibn Majah 2513 
It was narrated that Jabir bin 'Abdullah said:
“A man among us promised freedom to a slave after his death, and he did not have any property other than him (this slave). So the Prophet (ﷺ) sold him, and Ibn (Nahham), a man from Banu 'Adi, bought him.”
حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنْ عَمْرِو بْنِ دِينَارٍ، عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ، قَالَ دَبَّرَ رَجُلٌ مِنَّا غُلاَمًا وَلَمْ يَكُنْ لَهُ مَالٌ غَيْرُهُ فَبَاعَهُ النَّبِيُّ صلى الله عليه وسلم فَاشْتَرَاهُ ابْنُ النَّحَّامِ رَجُلٌ مِنْ بَنِي عَدِيٍّ ‏.‏
Reference : Sunan Ibn Majah 2513
In-book reference : Book 19, Hadith 2
English translation : Vol. 3, Book 19, Hadith 2513