The Book of Purification
1/166. Chapter:
The Junub Person Performing Wudu' When He Wants To Sleep
Sunan an-Nasai
أَخْبَرَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي سَلَمَةَ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ عَائِشَةَ، - رضى الله عنها - قَالَتْ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ إِذَا أَرَادَ أَنْ يَنَامَ وَهُوَ جُنُبٌ تَوَضَّأَ وُضُوءَهُ لِلصَّلاَةِ قَبْلَ أَنْ يَنَامَ .
It was narrated that 'Aishah said: "If the Messenger of Allah (ﷺ) wanted to sleep while he was Junub, he would perform Wudu' as for prayer before sleeping."
Reference : Sunan an-Nasa'i 258In-book reference : Book 1, Hadith 259English translation : Vol. 1, Book 1, Hadith 259