and likewise a woman who fornicates, or who takes a secret lover whose mistress she becomes and with whom alone she has illicit relations. For marriage to be lawful, the man must neither fornicate nor take a secret lover. If the woman is a prostitute who has intercourse with one man after another, her husband is not safeguarding her chastity against other men. Were he safeguarding her chastity, she would be chaste; if she is promiscuous, she is not chaste. Allah has permitted marriage only when men safeguard chastity rather than commit fornication. And if it is stipulated that he must not commit fornication with another woman—and thus must not spill his semen with anyone other than her—then this reinforces the point all the more.

The lexicographers say that sifāh means fornication. Ibn Qutaybah explained “seeking chastity” as “being married.” Regarding “not committing fornication,” he said: “Its root comes from the expression safahtu al-qirbah, meaning ‘I poured out the waterskin’s contents.’ Fornication was therefore called sifāh because the man pours out his reproductive fluid, and the woman pours out hers.”

Ibn Fāris said: “Sifāh is the spilling of sexual fluid without a contract or marriage; she is thus a woman who spills her fluid.”

Al-Zajjāj explained “seeking chastity” as “entering into a marriage contract.” Others besides these two explained it as “remaining chaste, not committing fornication.” Likewise, He says in Sūrat al-Nisā’:

“And lawful to you are all beyond these, provided that you seek them with your wealth in marriage, not in fornication.”

In these two verses, He stipulates that men be muhsinīn, not fornicators, with the letter sād pronounced with an i vowel. A muhsin is someone who safeguards another’s chastity; this is not muhsan, with an a vowel, the status stipulated in connection with the prescribed punishment. Thus, permission to marry is granted only to a man who safeguards the woman’s chastity rather than committing fornication. Whoever marries a prostitute while she continues in prostitution, without safeguarding her chastity against other men—so that she continues to have illicit relations with others just as she did before marriage—is engaging in fornication with her, not safeguarding her chastity. This is forbidden, as the Quran indicates.