Musannaf Ibn Abi Shayba 28:692

Zayd ibn al-Hubab narrated to us, he said: Ibn Abi Dhi’b narrated to me, from al-Qasim ibn ‘Abbas, from ‘Abdullah ibn Nayyar, from ‘Urwah, from ‘A’ishah: That the Messenger of Allah (may Allah bless him and grant him peace) was brought a gazelle [or a portion of meat], and he divided it equally between the free woman and the slave woman. And ‘A’ishah said: My father used to divide equally between the free man and the slave.