Mishkat al-Masabih 626
Abu Huraira reported God’s Messenger as saying:
Angels take turns among you by night and by day, and they all assemble at the dawn and the afternoon prayers. Those who spent the night among you then ascend, and their Lord asks them, yet He is best informed about them, “How did you leave My servants?” They reply, “We left them while they were praying, and we came to them while they were praying.” 

(Bukhari and Muslim.)
وَعَنْ أَبِي هُرَيْرَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسلم قَالَ: «يَتَعَاقَبُونَ فِيكُمْ مَلَائِكَةٌ بِاللَّيْلِ وَمَلَائِكَةٌ بِالنَّهَارِ وَيَجْتَمِعُونَ فِي صَلَاةِ الْفَجْرِ وَصَلَاةِ الْعَصْرِ ثُمَّ يَعْرُجُ الَّذِينَ بَاتُوا فِيكُمْ فَيَسْأَلُهُمْ رَبُّهُمْ وَهُوَ أَعْلَمُ بِهِمْ كَيْفَ تَرَكْتُمْ عِبَادِي فَيَقُولُونَ تَرَكْنَاهُمْ وَهُمْ يصلونَ وأتيناهم وهم يصلونَ»