"We were with the Messenger of Allah ﷺ when some of the people said: 'Why do you not stop with us to rest awhile, 0 Messenger of Allah ﷺ?' He said: 'I am afraid that you will sleep and miss the prayer.' Bilal said:'I will wake you up.' So they lay down and slept, and Bilal leaned back on his mount. Then the Messenger of Allah ﷺ woke up when the sun had already started to rise, and he said: '0 Bilal, what about what you told us?' He said: 'I have never slept like that before.' The Messenger of Allah ﷺ said: 'Allah, the Mighty and Sublime, takes your souls when He wills and sends them back when He wills.' Stand up 0 Bilal and call the people to prayer.' Then Bilal stood up and & called the Adhan, and they performed Wudu' - that is, when the sun had risen (fully) - "then he stood and lead them in prayer." (Using translation from Nasāʾī 846)  

كُنَّا مَعَ رَسُولِ اللهِ ﷺ إِذْ قَالَ بَعْضُ الْقَوْمِ لَوْ عَرَّسْتَ بِنَا يَا رَسُولَ اللهِ فَقَالَ «إِنِّي أَخَافُ أَنْ تَنَامُوا عَنِ الصَّلَاةِ» فَقَالَ بِلَالٌ أَنَا أَحْفَظُكُمْ فَاضْطَجَعُوا فَنَامُوا وَأَسْنَدَ بِلَالٌ ظَهْرَهُ إِلَى رَاحِلَتِهِ فَاسْتَيْقَظَ رَسُولُ اللهِ ﷺ وَقَدْ يَعْنِي طَلَعَ حَاجِبُ الشَّمْسِ فَقَالَ «يَا بِلَالُ أَيْنَ مَا قُلْتَ؟» قَالَ مَا أُلْقِيَتْ عَلَيَّ نَوْمَةٌ مِثْلُهَا قَطُّ قَالَ رَسُولُ اللهِ ﷺ «إِنَّ اللهَ قَبَضَ أَرْوَاحَكُمْ حِينَ شَاءَ فَرَدَّهَا حِينَ شَاءَ قُمْ يَا بِلَالُ فَآذِنِ النَّاسَ بِالصَّلَاةِ» فَقَامَ بِلَالٌ فَأَذَّنَ فَتَوَضَّأَ يَعْنِي حِينَ ارْتَفَعَتِ الشَّمْسُ ثُمَّ قَامَ فَصَلَّى بِهِمْ