Musnad Abu Ya'la al-Mawsili 150:403

Amr ibn Muhammad narrated to us, Mu'ammar ibn Sulayman al-Raqqi narrated to us, Hajjaj narrated to us, from Ikrimah, from Ibn Abbas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "There is no marriage except with a guardian." "And the ruler is the guardian for the one who has no guardian."