عَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا قَالَتْ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ إِذَا أَرَادَ أَنْ يَنَامَ (وَفِي رِوَايَةٍ: زِيَادَةُ وَهُوَ جُنُبٌ) تَوَضَّأَ وَضُوءَهُ لِلصَّلَاةِ
It is narrated from Sayyida Aisha (may Allah be pleased with her), she says: When the Messenger of Allah (peace and blessings be upon him) intended to sleep while he was in a state of janabah, he would perform ablution as for prayer.