What is the requirement for ritual cleansing if urine passes the boundary of the female sexual outlet (makhraj al-hayd)?
Chapter on Cleaning oneself (Istitabah) and Impurity (Hadath)
Al-Mughni
Book of Purification
Primary text
According to our companions, washing is obligatory if the urine passes into the outlet for menstruation, as this outlet is distinct from the urine outlet. This is because the urine outlet and the menstruation outlet are different orifices. Furthermore, if washing were required even when this spread is customary for her, the Prophet (peace be upon him) would have instructed his wives.
Supporting text
Alternatively, it is held that dry cleansing suffices because this spread is customary for her, similar to customary spread in other women, and if washing were required, the Prophet (peace be upon him) would have specified it to his wives.