If one manumits a male slave owned by two persons Sahih al-Bukhari 2521
Arabic hadith text
حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا سُفْيَانُ، عَنْ عَمْرٍو، عَنْ سَالِمٍ، عَنْ أَبِيهِ ـ رضى الله عنه ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ "مَنْ أَعْتَقَ عَبْدًا بَيْنَ اثْنَيْنِ، فَإِنْ كَانَ مُوسِرًا قُوِّمَ عَلَيْهِ ثُمَّ يُعْتَقُ "
Translation
Narrated Ibn `Umar
The Prophet (ﷺ) said, "Whoever manumits a slave owned by two masters, should manumit him completely (not partially) if he is rich after having its price evaluated."