He may be answered as follows:

This implies that everything Allah has forbidden would be valid—for example, being married to a woman and her paternal aunt at the same time, which is forbidden lest it lead to severing ties of kinship. It could then be said: “If this man’s argument is correct, this provides evidence that the marriage contract is valid, since, if it were invalid, no severing of kinship would occur.” This is ignorance.

The Lawgiver has explained the wisdom behind prohibiting what He has forbidden: if He permitted it, harm would necessarily follow. Thus, Allah’s words:

“You do not know; perhaps Allah will bring about a new situation after that,”

and the Prophet’s words, peace be upon him:

“A woman must not be married along with her paternal or maternal aunt, for if you do so, you will sever your ties of kinship,”

and similar statements explain that, were the act permitted, harm would result from it. It was therefore forbidden to prevent that harm. Harm arises from permitting the act and from performing it in the belief that it is permissible or valid. But when one believes it to be forbidden and invalid, and abides by the command of Allah and His Messenger, the harm does not arise. Rather, harm arises from disobeying the command of Allah and His Messenger.

Such harms involve tribulation and punishment. Allah Most High says:

“So let those who oppose his command beware lest a tribulation befall them or a painful punishment afflict them.”

As for the claim, “If the divorce were not binding, the harm would not occur,” the answer is:

That is precisely the purpose of the Lawgiver, may Allah bless him and grant him peace. He therefore prohibited it and ruled it invalid so that the harm would be removed. Otherwise, people would do it, believing it valid, and harm would necessarily follow.

This resembles the argument of someone who says: “Prohibiting something indicates that it is intended, that it has legal recognition, and that it may be called a sale, a marriage, or a fast.” They make such arguments concerning his prohibition of shighār (exchange marriage), his curse upon the man who marries a divorced woman to make her lawful again for her former husband and upon the former husband for whom this is done, and his prohibition of selling fruit before its ripeness becomes apparent