Musannaf Ibn Abi Shayba 13:2161

Abu Bakr narrated to us, he said: Waki' narrated to us, he said: Hammad bin Salamah narrated to us, from Muhammad bin Ziyad, from Abu Hurairah, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever buys a *musarrah* (an animal whose milk has been withheld in the udder to deceive the buyer), he has the choice. If he wishes, he may return it and return with it a *sa'* of dates."