Sahih Bukhari
Partnership
Volume: 003 / Book Number: 044 / Hadith Number: 671
Narrated Nafi:
Ibn 'Umar said, "Allah's Apostle said, 'If one manumits his share of a jointly possessed slave, and can afford the price of the other shares according to the adequate price of the slave, the slave will be completely manumitted; otherwise he will be partially manumitted.' " (Aiyub, a sub-narrator is not sure whether the saying " ... otherwise he will be partially manumitted" was said by Nafi' or the Prophet.)