Musnad Ahmad 30:409

'Abd al-Wahid narrated to us, Muhammad ibn 'Amr narrated to us, from Abu Salamah, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The orphan girl shall be asked for permission regarding herself. If she remains silent, that is her permission. And if she refuses, then there is no authority over her."