"Who will watch out for dawn for us, so that we do not sleep and miss the dawn prayer?" Bilal said: 'I will.' He turned to face the direction where the sun woke them up, then they got up. He said: 'Perform Wudu'.' Then Bilal called the Adhan and he prayed two Rak'ahs, and they prayed the two (Sunnah) Rak'ahs of Fajr, then they prayed Fajr." (Using translation from Nasāʾī 624)   

كَانَ رَسُولُ اللهِ ﷺ فِي سَفَرٍ فَقَالَ مَنْ يَكْلَؤُنَا اللَّيْلَةَ لَا نَرْقُدُ عَنْ صَلَاةِ الْفَجْرِ؟ فَقَالَ بِلَالٌ أَنَا فَاسْتَقْبَلَ مَطْلَعَ الشَّمْسِ فَضُرِبَ عَلَى آذَانِهِمْ فَمَا أَيْقَظَهُمْ إِلَّا حَرُّ الشَّمْسِ فَقَامُوا فَأَدَّوْهَا ثُمَّ تَوَضَّئُوا فَأَذَّنَ بِلَالٌ فَصَلَّوْا الرَّكْعَتَيْنِ ثُمَّ صَلَّوْا الْفَجْرَ