2118. The commodity that is sold and the payment acquired in return must possess the following five conditions:
1. Its measure must be known either by weight, volume, count or any similar method of measurement.
2. The item should be deliverable. If the seller—for example—sells an item that he is unable to deliver, but the buyer is able to acquire it, it will suffice. Therefore, if--for example—someone sells a horse that has run away, and neither of the parties is able to capture it, the transaction will be void.
However, if he sells a runaway horse along with something of value that is deliverable, the transaction will be valid even if the horse is not located. The more precautious measure—in the case of things other than runaway slaves—is that the seller should sell a commodity of value, and stipulate within the transaction that should the runaway be located, it will be the property of the buyer.
3. The details of the commodity and the item acquired in return, which are responsible for the difference in its price, should be specified.
4. The ownership of the commodity should be unconditional. Hence, the sale of a property that has been dedicated (waqf) is not permissible, except in the cases which will be mentioned later.
5. The commodity itself should be sold and not its benefits. Hence, if someone, for example, sells one year’s worth of benefits acquired from a house, it will not be valid. However, there is no problem if the buyer offers the benefits to his property instead of money, such as the case wherein he buys a carpet from an individual and in return he gives him a year’s worth of benefits to his house.
The rulings pertaining to these conditions will be elaborated in subsequent articles.
The endowed property should be sold by its trustee, and any use of the property acquired in return should also be carried out by him. In the event that he is not available, it should be carried out with the permission of the ¦¡kim al-shari’yy.
The same will apply if the endower stipulates that if the general interest is upheld by selling it, that it be sold.
In this case, if the buyer was not aware that the property has been rented out, or under the impression that the rental period is short, before he chooses to buy it, he can cancel the transaction upon finding out.