Maliks Muwatta Book 38, Hadith Number 3.
Section : People who Free Slaves and Own No Other Property.
Malik related to me from Yahya ibn Said and somebody else from al-Hasan ibn Abi al-Hasan al-Basri and from Muhammad ibn Sirin that a man in the time of the Messenger of Allah, may Allah bless him and grant him peace, freed six of his slaves while he was dying. The Messenger of Allah, may Allah bless him and grant him peace, drew lots between them and freed a third of those slaves.
Malik added that he had heard that the man did not have any property other than them.