Musnad Abu Ya'la al-Mawsili 110:270

Zuhayr narrated to us, Muhammad ibn Sabiq narrated to us, Ibrahim ibn Tahman narrated to us, from Abu al-Zubayr, from Ibn Abbas, that the Messenger of Allah (may Allah bless him and grant him peace) sent his wives ahead on the night of Jam' (Muzdalifah) before the crowding.