Musannaf Ibn Abi Shayba 18:604

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Ibn Abi Dhi’b, he said: Bashir al-Maktab narrated to me: That a woman granted *tadbir* (post-death emancipation) to a slave girl of hers, and she (the slave girl) committed a crime. Umar ibn Abd al-Aziz judged regarding her crime that it was upon her mistress, up to the value of the slave girl.