Or, according to the preponderant view, he may say: “These, for example, are ten cartons, which are yours for one hundred riyals: each carton is ten, and whatever you do not sell may be returned, with its proportionate amount deducted from the price.” We consider this permissible, because neither party is harmed and there is no injustice involved; moreover, the owner of the goods is willing to accept what remains.
What matters, then, is that the price of each individual item be specified; in that case, the arrangement is valid. Thus, food intended for consumption cannot be leased, though it may be sold.
His statement: “Nor may wax be leased for him to burn.” Wax likewise may not be leased for someone to burn. Wax is a solid substance that melts in fire, but it fuels the flame just as a wick does. Thus, if the lessee says, “I wish to lease this candle from you because I have guests tonight, for such-and-such an amount, for one or two hours,” the school holds that this is not permissible, because we do not know how much of the candle will be consumed. Shaykh al-Islam, may Allah have mercy on him, held that it is permissible. However, the Shaykh’s statement, may Allah have mercy on him, requires further qualification. The proper qualification is to say: it may either be measured by the length of the candle, such that he says, for example, “Its length is one handspan for ten riyals, and whatever is reduced from the handspan is charged proportionately.” In this case, it is known.
Or it may be estimated by the hour, where we know the candle’s rate of consumption by the hour and minute. This too is known.
His statement: “Nor may an animal be leased in order to take its milk, except in the case of a wet nurse.” An animal may not be leased in order to take its milk. An example is a man who has young lambs whose mother has died, so he leases a ewe from someone for a day or two until he can buy a ewe to suckle the lambs. This is not permissible, because what is contracted for in this case is the milk, and milk consists of discrete parts, whereas a lease cannot be made