Musannaf Ibn Abi Shayba 35:69

Mu'adh ibn Mu'adh narrated to us, he said: Ibn Jurayj informed us, from Sulayman ibn Musa, from al-Zuhri, from 'Urwah, from 'Aishah, who said: The Messenger of Allah (peace be upon him) said: "Any woman whose marriage is not contracted by the guardian (wali) or the guardians, then her marriage is void." He said it three times. "If he has consummated with her, then she is entitled to the dower (mahr) for what he has obtained from her. If they dispute, then the Sultan (ruler) is the guardian of the one who has no guardian."