It was narrated that:
Aisha and Ibn Abbas said: "The Messenger of Allah said: 'There is no marriage except with a guardian.' "According to the Hadith of Aishah: "And the ruler is the guardian of the one who does not have a guardian. " (FR)
English reference (FR): Vol. 3, Book 9, Hadith 1880 (FR)
Arabic reference (FR): Book 9, Hadith 1954 (FR)