Sahih Bukhari
Sahih Bukhari Volume 001, Book 005, Hadith Number 285.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 05. Bathing (Ghusl)
Narated By 'Umar bin Al-Khattab : I asked Allah's Apostle "Can any one of us sleep while he is Junub?" He replied, "Yes, if he performs ablution, he can sleep while he is Junub."