His statement, “It is valid in the case of a worker and a wet nurse in return for their food and clothing,” means that it is valid to hire a worker in return for his food and clothing: for example, to hire someone to work for you in exchange for his food, drink, clothing, and lodging. Here, the wage is known by customary practice, so it is understood according to the custom, which is the minimum sufficiency. Thus, if the worker says, “I was hired in return for food, but I want the food of kings”—that is, the finest possible food—his request is not granted; rather, he is given the food customary for someone of his standing.

His statement, “and a wet nurse”: this is a nursing woman. It is permissible to hire her in return for her food and clothing, due to the saying of Allah, Exalted is He:

“If they suckle your children, then give them their payment, and consult together in a fair manner. But if you disagree, then another woman may suckle the child for the father.” [Surah al-Talaq 65:6]

He mentioned payment without specifying it, and He says:

“The father of the child shall provide for the mothers’ food and clothing according to what is fair.” [Surah al-Baqarah 2:233]

It is therefore permissible to hire a woman to nurse a child in return for her food and clothing, and the matter is determined by customary practice.

Is it valid to hire a riding animal in return for its food, drink, and whatever is necessary to sustain its life? The apparent meaning of the author’s words is that it is not valid, since he confined this matter to a human worker and a wet nurse as well. The correct view, however, is that it is permissible to hire an animal in return for undertaking its care—providing it with food, drink, and protection from cold and heat—because there is no difference between it and a worker: in both cases, one is receiving a benefit. In this matter, custom is referred to.

Is it valid to rent a house in return for repairing whatever collapses from it? It is not valid, because this is unknown: a great deal of it may collapse, or nothing at all may collapse, so the wage is entirely unknown. The exception is where the collapsed portion already exists, and he says, “I have rented it to you in return for repairing what has already collapsed,” and it is known. In that case, the hire is valid, because the wage is known through observation.

If he says, “I have rented this house to you for ten thousand and the repair of whatever collapses”