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 305 c
Arabic hadith text
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، وَابْنُ، بَشَّارٍ قَالاَ حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، ح وَحَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ، قَالَ حَدَّثَنَا أَبِي قَالَ، حَدَّثَنَا شُعْبَةُ، بِهَذَا الإِسْنَادِ قَالَ ابْنُ الْمُثَنَّى فِي حَدِيثِهِ حَدَّثَنَا الْحَكَمُ، سَمِعْتُ إِبْرَاهِيمَ، يُحَدِّثُ
Translation
This hadith has been transmitted by Shu'ba with the same chain of transmitters. Ibn at-Muthanna said in his narration
AI-Hakam narrated to us who heard from Ibrahim narrating that.