Is the option (Khiyar) established when purchasing a 'Musrat' (animal whose milk has been withheld) that is not livestock (An'am)?
Chapter on Selling the Musarrah (Animal with milk retained in udder)
Al-Mughni
Book of Sales
Primary text
The option (Khiyar) is established upon the purchase of a withheld-milk animal other than livestock, such as a female slave, a female donkey, or a horse. This view is chosen by Ibn Aqil and is apparent in the Shafi'i madhhab. The evidence for this is the generality of the saying: 'Whoever buys a Musrat and whoever buys a Mahfulah' (an animal whose milk has been artificially increased). Furthermore, withholding the milk in these animals involves something that affects the price, thus establishing the option, similar to withholding milk in livestock. This is because the milk of a human female is desired for nursing, and she is sought after as a wet nurse, which improves her breasts; hence, if the buyer stipulated plentiful milk and it turned out otherwise, the right to nullify the sale is established. If it were not intended, its stipulation would not establish the right to nullify upon its absence. Moreover, the female donkey and the horse are desired for their offspring. If the seller revokes the sale, no substitute for the milk is required, nor is anything returned with the animal, because this specific milk is not typically traded or compensated for.
Supporting text
The second opinion is that the option is not established because the milk of such animals is not usually substituted or sought after in the same manner as the milk of livestock. The hadith is specific to livestock, and analogy (Qiyas) to other animals is invalid because the intent regarding livestock milk is more common. The general wording in the hadith is intended to apply only to the specific case, as evidenced by the command to return it with a Sa' of dates, which is not applicable to the milk of others. Since the ruling was issued generally and specifically within one issue, the general term should be interpreted according to the specific term, meaning the general term in one narration refers to the specific term in the other narration.