كتاب الطهارة وسننها
1  
The Book of Purification and its Sunnah
(99)
Chapter: Those who say that the sexually impure should not sleep until he performs ablution like his ablution for prayer
(99)
باب مَنْ قَالَ لاَ يَنَامُ الْجُنُبُ حَتَّى يَتَوَضَّأَ وُضُوءَهُ لِلصَّلاَةِ ‏
Sunan Ibn Majah 586
It was narrated from Abu Sa'eed Khudri that:
He used to become sexually impure at night, then he would want to sleep. The Messenger of Allah told him to perform ablution and then go to sleep.
حَدَّثَنَا أَبُو مَرْوَانَ الْعُثْمَانِيُّ، مُحَمَّدُ بْنُ عُثْمَانَ حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ مُحَمَّدٍ، عَنْ يَزِيدَ بْنِ عَبْدِ اللَّهِ بْنِ الْهَادِ، عَنْ عَبْدِ اللَّهِ بْنِ خَبَّابٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، أَنَّهُ كَانَ تُصِيبُهُ الْجَنَابَةُ بِاللَّيْلِ فَيُرِيدُ أَنْ يَنَامَ فَأَمَرَهُ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ أَنْ يَتَوَضَّأَ ثُمَّ يَنَامَ ‏.‏
Grade: Sahih (Darussalam)
Reference : Sunan Ibn Majah 586
In-book reference : Book 1, Hadith 320
English translation : Vol. 1, Book 1, Hadith 586