Sahih al-Bukhari Book 49, Hadith 8
The Prophet (ﷺ) said, "He who manumits his share of a slave and has money sufficient to free the
remaining portion of that slave's price (justly estimated) then he should manumit him (by giving the
rest of his price to the other co-owners)." Nafi` added, "Otherwise the slave is partially free." Aiyub is
not sure whether the last statement was said by Nafi` or it was a part of the Hadith.
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.
`Ubaidullah narrated as above in brief.
That he used to give his verdict regarding the male or female slaves owned by more than one master, one of whom may manumit his share of the slave. Ibn `Umar used to say in such a case, "The manumitted should manumit the slave completely if he has sufficient money to pay the rest of the price of that slave (which is to be justly estimated) and the other shareholders are to take the price of their shares and the slave is freed (released from slavery)." Ibn `Umar narrated this verdict from the Prophet.