What is the ruling on a father marrying his daughter in a sham marriage, and is it permissible for the questioner to marry this girl and consummate the marriage, knowing that her marriage is a sham, so that she can obtain a sham divorce and then a formal marriage afterward?

The ruling on a "paper marriage" varies according to two situations:

1. If the marriage fulfills the conditions of a valid Islamic marriage (such as the guardian and witnesses): In this case, the marriage is Islamically valid, and it makes no difference whether it was intended seriously or jokingly, based on the Prophet's (peace be upon him) saying: "There are three matters, serious in which are serious, and joking in which are serious: marriage, divorce, and return (to one's wife)."

2. If it does not fulfill the conditions of validity: In this case, the marriage is Islamically null and void, whether it is documented or not. It is considered tampering with a great ritual of Islam, as Allah (the Most High) says: "And do not take the verses of Allah in ridicule."

The permissibility of anyone marrying this woman depends on the details of her situation. It is not permissible to marry her unless she is free from Islamic impediments, including that she is not already bound by a valid Islamic contract (even if some scholars consider it flawed).

As for a person merely telling his colleagues that this woman is his wife, this does not make her his wife. Rather, she remains a stranger to him, and it is not permissible for him to be in seclusion with her or live with her. The declaration of marriage referred to is the valid marriage that fulfills the conditions, and it is recommended, not obligatory, according to the majority of jurists.