(4) باب إِذَا أَعْتَقَ عَبْدًا بَيْنَ اثْنَيْنِ أَوْ أَمَةً بَيْنَ الشُّرَكَاءِ
Narrated Ibn `Umar:
Allah's Messenger (ﷺ) said, "Whoever manumits his share of a slave, then it is essential for him to get that slave manumitted' completely as long as he has the money to do so. If he has not sufficient money to pay the price of the other shares (after the price of the slave is evaluated justly), the manumitted manumits the slave partially in proportion to his share.
Reference: Sahih al-Bukhari 2523
In-book reference: Book 49, Hadith 7
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 3, Book 46, Hadith 699