Musnad Abu Ya'la al-Mawsili 145:3

Ibrahim ibn al-Hajjaj al-Sami narrated to us, Abd al-Aziz ibn al-Mukhtar narrated to us, Shu'bah ibn al-Habhab narrated to us, Anas ibn Malik narrated to us, that the Prophet, peace and blessings of Allah be upon him, emancipated Safiyyah and made her emancipation her dowry.