its milk for a specified period; this is like hiring a mount to ride for a specified period. If the usual yield changes, this constitutes a change in the benefit obtained, entitling the lessee either to rescind the contract or to compensation. The same applies to leasing someone an orchard to use for one or two years, as ‘Umar ibn al-Khattāb did when he leased out the orchard of Usayd ibn al-Hudayr for three years, received the payment, and used it to discharge a debt Usayd owed.

If the lessee himself tends these animals, the arrangement is a lease, and there is even stronger reason to permit it than the hiring of a wet nurse. If, however, the livestock’s owner feeds, waters, and shelters them, while the person seeking their milk is concerned only with the milk and has hired them to suckle his young livestock, this is like hiring a wet nurse. If he is to collect the milk himself, this resembles hiring a wet nurse to provide milk generally, rather than to nurse a particular child. This may be called a sale or a lease; the dispute is merely terminological.

If it is said that this is the sale of something that does not yet exist, the reply is: Yes, but no principle of Islamic law prohibits every sale of something not yet in existence. Rather, something that does not yet exist may be sold when there is a need for its sale and it is known through customary experience, just as fruit may be sold once it begins to show signs of ripeness. This is valid according to the majority of scholars, as the Sunnah indicates, even though the portions that develop later do not yet exist but are nevertheless included in the contract. Likewise,