Hadith 584
Chapter 99: Those who say that the sexually impure should not sleep until he performs ablution like his ablution for prayer - كتاب الطهارة وسننها
حَدَّثَنَا مُحَمَّدُ بْنُ رُمْحٍ الْمِصْرِيُّ، أَنْبَأَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنِ الزُّهْرِيِّ، عَنْ أَبِي سَلَمَةَ، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ إِذَا أَرَادَ أَنْ يَنَامَ وَهُوَ جُنُبٌ تَوَضَّأَ وُضُوءَهُ لِلصَّلاَةِ .
It was narrated that 'Aishah said:
"When the Messenger of Allah wanted to sleep and he was sexually impure, he would perform ablution as for prayer."
Reference : Sunan Ibn Majah 584
In-book reference : Book 1, Hadith 318