Sahih al-Bukhari 7429
Narrated Abu Huraira:
Allah's Messenger (ﷺ) said, "(A group of) angels stay with you at night and 
     (another group of) angels by daytime, and both groups gather at the 
     time of the 'Asr and Fajr prayers. Then those angels who have stayed 
     with you overnight, ascend (to Heaven) and Allah asks them (about you)
     ---- and He knows everything about you. "In what state did you leave 
     My slaves?' The angels reply, 'When we left them, they were praying, 
     and when we reached them they were praying.' "
حَدَّثَنَا إِسْمَاعِيلُ، حَدَّثَنِي مَالِكٌ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏
"‏ يَتَعَاقَبُونَ فِيكُمْ مَلاَئِكَةٌ بِاللَّيْلِ وَمَلاَئِكَةٌ بِالنَّهَارِ، وَيَجْتَمِعُونَ فِي صَلاَةِ الْعَصْرِ وَصَلاَةِ الْفَجْرِ، ثُمَّ يَعْرُجُ الَّذِينَ بَاتُوا فِيكُمْ فَيَسْأَلُهُمْ وَهْوَ أَعْلَمُ بِكُمْ فَيَقُولُ كَيْفَ تَرَكْتُمْ عِبَادِي فَيَقُولُونَ تَرَكْنَاهُمْ وَهُمْ يُصَلُّونَ وَأَتَيْنَاهُمْ وَهُمْ يُصَلُّونَ ‏"‏‏.‏