What is the legal implication when a husband tells his wife, 'If I have intercourse with you, you are divorced'?
Chapter on Explicit Divorce and Others
Al-Mughni
Book of Divorce
Primary text
The oath or condition refers to sexual intercourse (jama'a). This interpretation is adopted because when the term 'wat' (to tread/touch/have intercourse) is directed towards the wife, it is customarily understood as sexual intercourse. This is supported by the usage in Prophetic narrations, such as the saying: 'No pregnant woman should be subjected to intercourse until she delivers, and no woman whose status is uncertain should be subjected to intercourse until she completes one menstrual cycle.' Therefore, the term must be interpreted according to this customary meaning, similar to other conventional terms like 'dheena' (female passenger) or 'rawiyah' (water-bearer). The oath is broken only when the glans penis completely disappears into the vagina.
Supporting text
Muhammad ibn al-Hasan stated that the oath refers specifically to intercourse through the penis, as that is the literal meaning. It is reported from him that if he claims he intended sexual intercourse when he used the term 'wat', this claim would not be accepted in a legal ruling.