Maliks Muwatta Book 28, Hadith Number 9.

Section : The Bride-Price and Un-returnable Gifts.

Yahya related to me from Malik from Yahya ibn Said that Said ibn al-Musayyab had said that Umar ibn al-Khattab said, “If a man marries a woman who is insane, or has leprosy or white leprosy, without being told of her condition by her guardian, and he has sexual relations with her, she keeps her bride-price in its entirety. Her husband has damages against her guardian.”

Malik said, “The husband has damages against her guardian when the guardian is her father, brother, or one who is deemed to have knowledge of her condition. If the guardian who gives her in marriage is a nephew, a mawla or a member of her tribe who is not deemed to have knowledge of her condition, there are no damages against him, and the woman returns what she has taken of her bride-price, and the husband leaves her whatever amount is thought to be fair.”