the Prophet ﷺ said: “The earnings of a prostitute are impure.” (1) Moreover, it is intercourse which both the active and passive parties believe to be unlawful; therefore, it entails no financial liability.
This is what the author has established both explicitly and by implication: explicitly, that the woman with whom adultery is committed under coercion is entitled to a dowry; and by implication, that no dowry is due to the woman with whom adultery is committed consensually.
The correct view is that no dowry is due in either case, because Allah, Exalted is He, has prescribed a known legal punishment for adultery; thus, we do not add to what Allah has prescribed. Nor can we analogize this intercourse—which the man engaging in it believes to be unlawful—to lawful intercourse. Rather, the prescribed punishment is carried out upon him: if the man is unmarried—that is, he has never married before—his punishment is one hundred lashes and one year of exile. If he has previously married and consummated the marriage with his wife, and the conditions of iḥṣān are fulfilled, then he is stoned to death.
His statement, “Nor is compensation for the loss of virginity due along with it,” means that if he commits adultery with a woman by coercion, and she is a virgin whose virginity is thereby lost, then, according to the madhhab, he must pay her the customary dowry. The customary dowry includes compensation for the loss of virginity, because the dowry will be assessed according to that of a virgin. Thus, compensation for the loss of virginity has already been included, and it cannot be imposed upon him a second time.
According to the view we have deemed stronger—that a woman with whom adultery is committed, whether under coercion or consensually, is not entitled to a dowry—we say that he must pay compensation for the loss of virginity if she was a virgin and he committed adultery with her by coercion, because he destroyed her virginity through something that normally destroys it.