Musnad Ahmad 1160:2

Sufyan ibn 'Uyaynah narrated to us, from Yahya—meaning Ibn Sa'id—who said: Al-Qasim narrated to us, from 'Abd al-Rahman ibn Yazid and Mujammi', two elders from the Ansar, that Khansa's father married her off, and she disliked that, so the Messenger of Allah (peace and blessings of Allah be upon him) annulled it.