Sahih Muslim Book 10, Hadith Number 3637.

Chapter : Command pertaining to the selling of animal whose udder is tied up.

Abu Huraira (Allah be pleased with him) reported Allah’s Messenger (may peace be upon him) as saying: He who buys a goat having its udder tied up has two courses left for him. He may retain it, and if he desires may return it along with a sa’ of dates and not wheat.