It is permissible for one who is junub to sleep, but it is recommended for him to perform wudu’, and wash his private parts if he wants to eat, drink, sleep, or have intercourse Sahih Muslim 309
Arabic hadith text
حَدَّثَنَا الْحَسَنُ بْنُ أَحْمَدَ بْنِ أَبِي شُعَيْبٍ الْحَرَّانِيُّ، حَدَّثَنَا مِسْكِينٌ، - يَعْنِي ابْنَ بُكَيْرٍ الْحَذَّاءَ - عَنْ شُعْبَةَ، عَنْ هِشَامِ بْنِ زَيْدٍ، عَنْ أَنَسٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَيَطُوفُ عَلَى نِسَائِهِ بِغُسْلٍ وَاحِدٍ .
Translation
Anas reported
The Messenger of Allah (ﷺ) used to have sexual intercourse with his wives with a single bath.