Ahmad said: There is no harm if one rents for a described and known food. The same is held by Al-Shafi'i. Allah the Almighty said, reporting about Shu'ayb, that he said: {I wish to marry you one of these two daughters of mine, on condition that you serve me for eight years}, so he made the marriage the compensation for the service. Abu Hanifa said, according to what was narrated from him: It is not permissible to rent a house in exchange for living in another, and it is not permitted unless (29) the genus of the benefit differs, such as living in a house in exchange for the benefit of an animal; because in his view, a single genus prohibits deferred exchange (nasi'ah). Al-Thawri disliked renting for described food. The correct view is its permissibility, which is the opinion of Ishaq, the proponents of reason (Ashab al-Ra'y), and the analogical deduction (qiyas) of the view of Al-Shafi'i; because it is compensation that is permissible in a sale, so it is permissible in a rental, like gold and silver. What Abu Hanifa said is not correct; because benefits in a rental are not subject to the estimation of deferred exchange (nasi'ah), and even if it were a deferred exchange, it would not be permitted in two different genera, because it would be selling a debt for a debt.

Section: If a man hires someone to skin an animal for him in exchange for its hide, it is not permissible; because it is not known whether the hide will come off intact or not, and whether it is thick or thin. Furthermore, because it is not permissible for it to be a price in a sale, it is not permissible for it to be compensation in a rental, like other unknown matters. If he skins it for that, he is entitled to the wage of his equivalent work (ajr al-mithl). If he hires him to remove a carcass in exchange for its hide, the invalidity is more pronounced; because the hide of a carcass is impure (najis) and its sale is not permissible, and it has ceased to be property upon its death. If he does it, he is also entitled to the wage of his equivalent work.

Section: If a man hires a shepherd for his sheep in exchange for a third, a half, or all of their milk, offspring, wool, and hair, it is not permissible. Ahmad stated this in a report by Ja'far ibn Muhammad al-Nasa'i (30); because the wage is not known, and it is not fit to be compensation in a sale. Isma'il ibn Sa'id said: I asked Ahmad about a man who gives a cow to another man on the condition that he feeds and cares for it (31), and whatever offspring it produces