until the purchaser is able [to gather the fruit, just as the seller of a crop is responsible for completing its watering until the purchaser is able] to reap the crop. This forms part of fully delivering what was sold, and the cost of delivery falls upon the seller, as with measuring by volume and weighing. By contrast, one who leases the trees to someone who tends them until they bear fruit is like one who leases land to someone who cultivates it until it produces crops. The lessor need not perform any work whatsoever; he is required only to enable the lessee to perform the work through which the fruit and crops are produced.
Yet it may be objected: “The consistent implication of this argument is that it should be permissible to lease livestock to someone who feeds and waters them and milks them.”
It is replied: If, under one of the two reported positions, we permit livestock to be entrusted to someone who feeds and waters them in exchange for a share of their milk and offspring, then it is also permissible to entrust them to someone who tends them for their milk and offspring in return for a guaranteed payment.
If it is asked, “Why, then, should it not be permissible to lease them for the purpose of milking them, just as hiring a wet nurse is permissible?”
It is replied: “Hiring a wet nurse means engaging her to nurse, with the corresponding work for livestock being performed by their owner. The wet nurse herself nurses the child. Since she is the one who renders the benefit, the analogous arrangement is one in which the lessor himself renders the benefit of nursing; in that case, analogy dictates that it is permissible. If a man owned sheep and hired another man’s sheep to nurse them, there would be nothing impermissible about this. By contrast, if the lessee himself milks the milk or takes possession of it, he is purchasing the milk; he is neither receiving a usufruct nor obtaining the tangible product through labor. This resembles purchasing fruit: milking is like picking it, and it is this that was prohibited