What is the ruling regarding an unmarried girl who experiences a yellowish discharge (ṣufra) after the cessation of menstrual bleeding in three forms: (it ceases on the eleventh day, or continues until the fifteenth or sixteenth day, or continues uninterrupted from one menstruation to the next)? And should she wait 15 days, or should she perform ghusl upon the appearance of the yellowish discharge and consider herself a mustahāḍah (one experiencing irregular vaginal bleeding)?

The sign of purity is dryness or the white discharge. Whenever a woman sees dryness, she should perform ghusl and pray. The yellowish and brownish discharges are considered menstruation only during the period of one's usual cycle, not thereafter. After the end of the usual cycle, they are considered istihada (non-menstrual bleeding) which necessitates performing ablution for each prayer after its time has begun. As for white discharges, they are not considered part of the yellowish or brownish discharges, and the cessation of the yellowish and brownish discharges is a valid sign of purity.