Sayyidah Aisha (may Allah be pleased with her) narrates that when the Messenger of Allah (peace and blessings be upon him) was in a state of major ritual impurity (janabah) and intended to sleep, he would wash his private parts and perform ablution as he did for prayer.
Hadith Referenceاللؤلؤ والمرجان / كتاب الحيض / 176
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 5 كتاب الغسل: 27 باب الجنب يتوضأ ثم ينام»