Perform ritual washing after certain activities such as sexual intercourse or menstruation according to Islamic teachings .

This hadith explains why ghusl is obligatory in Islam. Ghusl is a ritual washing which must be performed after certain activities such as sexual intercourse or menstruation. According to this hadith, ghusl becomes obligatory when two circumcised parts come into contact with each other. This means that if a man and woman engage in sexual intercourse then they must perform ghusl afterwards in order to be considered clean and pure again according to Islamic teachings. The Prophet Muhammad's wife A'isha used an analogy of a chick crowing with other cocks when it hears them crowing in order to explain why ghusl becomes necessary after certain activities have been performed.