Musannaf Ibn Abi Shayba 13:1780

Abu Bakr narrated to us, he said: Ibn Abi Za’idah narrated to us, from Zakariya, from ‘Amir, regarding a slave who was between two men, one of whom emancipated his share. He said: His emancipation is completed. If he [the emancipator] does not have wealth, the slave shall work to earn the [value of the] half. And the *wala’* (right of inheritance/patronage) shall be for the one who emancipated.