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
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا ابْنُ عُلَيَّةَ، وَوَكِيعٌ، وَغُنْدَرٌ، عَنْ شُعْبَةَ، عَنِ الْحَكَمِ، عَنْ إِبْرَاهِيمَ، عَنِ الأَسْوَدِ، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم إِذَا كَانَ جُنُبًا فَأَرَادَ أَنْ يَأْكُلَ أَوْ يَنَامَ تَوَضَّأَ وُضُوءَهُ لِلصَّلاَةِ .
'A'isha reported: Whenever the Messenger of Allah (ﷺ) had sexual intercourse and intended to eat or sleep, he performed the ablution of prayer.