Evidence that sleeping while sitting does not invalidate wudu’
حَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا إِسْمَاعِيلُ ابْنُ عُلَيَّةَ، ح وَحَدَّثَنَا شَيْبَانُ بْنُ فَرُّوخَ، حَدَّثَنَا عَبْدُ الْوَارِثِ، كِلاَهُمَا عَنْ عَبْدِ الْعَزِيزِ، عَنْ أَنَسٍ، قَالَ أُقِيمَتِ الصَّلاَةُ وَرَسُولُ اللَّهِ صلى الله عليه وسلم نَجِيٌّ لِرَجُلٍ - وَفِي حَدِيثِ عَبْدِ الْوَارِثِ وَنَبِيُّ اللَّهِ صلى الله عليه وسلم يُنَاجِي الرَّجُلَ - فَمَا قَامَ إِلَى الصَّلاَةِ حَتَّى نَامَ الْقَوْمُ .
Anas reported: (The people) stood up for prayer and the Messenger of Allah (ﷺ) was whispering to a man, and in the narration of 'Abd al-Warith (the words are): The Messenger of Allah (ﷺ) was having a private conversation with a man, and did not start the prayer till the people dozed off.