It is narrated from Hazrat Aisha (may Allah be pleased with her) that when the pure wives of the Prophet (peace and blessings be upon him) were in their menstrual periods, the Prophet (peace and blessings be upon him) would have intimacy with his wives over the waist-wrapper, and when the Prophet (peace and blessings be upon him) wished to sleep in a state requiring ghusl (ritual bath), he would perform ablution as for prayer.