Language:
كتاب الإكراه
89  
(Statements made under) Coercion
(4)
Chapter: If someone gives a slave as a present or sold him under coercion, his deed is invalid
(4)
باب إِذَا أُكْرِهَ حَتَّى وَهَبَ عَبْدًا أَوْ بَاعَهُ لَمْ يَجُزْ
Sahih al-Bukhari 6947

Narrated Jabir:

A man from the Ansar made his slave, a Mudabbar. And apart from that slave he did not have any other property. This news reached Allah's Messenger (ﷺ) and he said, "Who will buy that slave from me?" So Nu'aim bin An-Nahham bought him for 800 Dirham. Jabir added: It was a coptic (Egyptian) slave who died that year.

حَدَّثَنَا أَبُو النُّعْمَانِ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ عَمْرِو بْنِ دِينَارٍ، عَنْ جَابِرٍ ـ رضى الله عنه ـ أَنَّ رَجُلاً، مِنَ الأَنْصَارِ دَبَّرَ مَمْلُوكًا، وَلَمْ يَكُنْ لَهُ مَالٌ غَيْرُهُ، فَبَلَغَ ذَلِكَ رَسُولَ اللَّهِ صلى الله عليه وسلم فَقَالَ ‏ "‏ مَنْ يَشْتَرِيهِ مِنِّي ‏"‏‏.‏ فَاشْتَرَاهُ نُعَيْمُ بْنُ النَّحَّامِ بِثَمَانِمِائَةِ دِرْهَمٍ‏.‏ قَالَ فَسَمِعْتُ جَابِرًا يَقُولُ عَبْدًا قِبْطِيًّا مَاتَ عَامَ أَوَّلَ‏.‏
Reference : Sahih al-Bukhari 6947
In-book reference : Book 89, Hadith 8
USC-MSA web (English) reference : Vol. 9, Book 85, Hadith 80
  (deprecated numbering scheme)