to the ruling of Allah and His Messenger, peace and blessings be upon him. Thus, a prohibition pertaining to the act itself entails its invalidity. Hence, if a person fasts on the day of Eid, his fast is unlawful and invalid, because it is prohibited. Likewise, if he sells over his brother’s sale, the sale is unlawful and invalid.
His statement, “and the contract is invalid,” explicitly affirms the invalidity of the contract. Some scholars maintain that the contract is valid, because the prohibition in this case does not relate to the essence of the subject matter of the contract; rather, it relates to an external matter—namely, transgressing against a Muslim. Accordingly, the contract is unlawful but valid.
This is supported by the fact that if the person whose sale was undercut were to give permission to the one who sold over his sale, the contract would be valid and there would be nothing wrong with it. This shows that the prohibition does not relate to the essence of what is prohibited, and that the contract is valid despite the sin involved. However, the position of the school is a matter of public policy: it prevents transgression against people, and is therefore a sound view.
Question: If someone hires over his brother’s hiring, what is the ruling?
Answer: The ruling is the same, because hiring is the sale of benefits.
Likewise, proposing marriage over his brother’s proposal is impermissible, because the Prophet, peace and blessings be upon him, prohibited this (1), and because the underlying reason is the same.
Whoever sells a ribawi item on deferred terms and takes in exchange for its price something that may not be sold for it on deferred terms, or purchases something for cash at less than what he sold it for on deferred terms—not the reverse—is not permitted to do so, even if he repurchases it with something of a different kind, after receiving its price, after its attributes have changed, or from someone other than its purchaser. However, if his father or son purchases it, it is permitted.
His statement, “Whoever sells a ribawi item on deferred terms,” means: for a deferred price.
His statement, “and takes in exchange for its price,” means: the price of that ribawi item.
His statement, “something that may not be sold”: the implied subject of “be sold” refers back to the ribawi item.