Narrated `Aisha: Whenever the Prophet intended to sleep while he was Junub, he used to wash his private parts and perform ablution like that for the prayer.
Hadith Referenceصحيح البخاري / كتاب الغسل / 288
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة
Narrated `Abdullah bin `Umar: `Umar bin Al-Khattab told Allah's Apostle, "I became Junub at night." Allah's Apostle replied, "Perform ablution after washing your private parts and then sleep."
Hadith Referenceصحيح البخاري / كتاب الغسل / 290
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة