عن ابْنِ عَبّاسٍ رَضِيَ اللهُ عَنْهُما أَنَّ رَسُوْلَ اللهِ صَلَّى الله عليه و سلم قَالَ: طَهِّرُوْا هذِهِ الْأجْسَادَ طَهَّرَكُمُ اللهُ فَإنَّهُ لَيْسَ مِنْ عَبْدٍ يَبِيْتُ طَاهِرًا إلاّ بَاتَ فِي شِعَارِهِ مَلَكٌ لاَيَنْقَلِبُ سَاعَةً مِنَ اللَيْلِ إلاَّ قَالَ : اللّهُمَّ اغْفِرْ لِعَبْدِكَ فَإنَّهُ بَاتَ طَاهِرًا (رواه الطّبراني في الأوسط رقم 5087 )
Hadhrat Abdullah bin `Abbaas (Radhiyallahu Anhu) reports that Rasulullah (Sallallahu Alaihi Wasallam) said, “Maintain cleanliness in regard to your bodies and Allah Ta’ala will purify you. Indeed whichever person sleeps in the state of wudhu, an angel (is appointed) to spend the night with him. If at any part of the night he turns (changes his sleeping posture), the angel makes duaa for him in the following words: O Allah! Forgive your servant for indeed he had retired to bed in the state of wudhu.”