It is narrated from Hazrat Aisha (may Allah be pleased with her) that sometimes ghusl (ritual bath) would become obligatory upon the Prophet (peace and blessings be upon him) and he would sleep. When he woke up, he would perform ghusl, and when he went out, drops of water would be dripping from his head. Then the Prophet (peace and blessings be upon him) would fast for the remainder of that day.