The sale id a slave who is promised to be manumitted
حَدَّثَنَا ابْنُ نُمَيْرٍ، حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا إِسْمَاعِيلُ، عَنْ سَلَمَةَ بْنِ كُهَيْلٍ، عَنْ عَطَاءٍ، عَنْ جَابِرٍ ـ رضى الله عنه ـ قَالَ بَاعَ النَّبِيُّ صلى الله عليه وسلم الْمُدَبَّرَ.
Narrated Jabir: The Prophet (ﷺ) sold a Mudabbar (on behalf of his master who was still living and in need of money).