What recourse does a buyer have upon discovering they purchased an animal whose milk was withheld (Musrah) without prior knowledge?
Chapter on Selling the Musarrah (Animal with milk retained in udder)
Al-Mughni
Book of Sales
Primary text
The buyer who purchases a Musrah animal, being unaware of the deception, possesses the option (khiyar) to either return the animal or retain it. This opinion is held by Ibn Mas'ud, Ibn Umar, Abu Hurairah, Anas, Malik, Ibn Abi Layla, Al-Shafi'i, Ishaq, Abu Yusuf, and the majority of scholars. The legal basis is the authentic Hadith of Abu Hurairah stating the buyer is in "the better of two options" after milking it, allowing retention or return with a measure of dates. Another narration by Ibn Umar specifies the option lasts for three days, requiring the return of the milk's equivalent in grain if returned.
Supporting text
Abu Hanifa and Muhammad held that the buyer has no option to return the animal, arguing that withholding milk is not a defect (aib). They reason that if the animal yielded less milk than similar ones without being withheld, the buyer could not return it, and deception concerning something that is not a defect does not establish the option. They further analogize this to fattening an animal, causing temporary swelling, which also does not grant return rights.