Abu Dawud
Book Of Emancipation Of Slaves
Book Number: 024 / Hadith Number: 3922
Narated By Usamah ibn Umayr al-Huzali : (This is Abu Walid's version): A man emancipated a share in a slave and the matter was mentioned to the Prophet (pbuh). He said: Allah has no partner.
Ibn Kathir added in his version: The Prophet (pbuh) allowed his emancipation.