Musannaf Ibn Abi Shayba 13:3270

Abu Bakr narrated to us, he said: Ubayd Allah ibn Musa narrated to us, he said: Sufyan narrated to us, from Ash'ath, from Ali ibn Mudrik, that a dispute was brought before al-Dahhak ibn Qays regarding a slave girl in whom he found a *dubaylah* (an abscess or internal ulcer), and it is an old ailment known not to be something that occurs recently. So he ruled that she be returned to the seller. And Sufyan said: The statement of al-Dahhak is more beloved to me than the statement of Shurayh, if it is known that it is not something that occurs recently, that it should be returned, and he requires the oath of the buyer that he did not see it before he bought it, and that he did not accept it after he saw it.