Abu Dawud Book 24, Hadith Number 3924.

Chapter : Emancipation of a share in a slave.

Narated By N/A : Qatadah narrated with his chain of narrators: The Prophet (may peace be upon him) said: If a man emancipates a slave shared by him with another man, his emancipation rests with him (who emancipated his share). This is the version of Ibn Suwaid.