Sahih Muslim 2499
Sahih Muslim · Book 44: The Book of the Merits of the Companions · The Virtues Of The Ash'aris (RA)
Abu Musa reported that Allah's Messenger (ﷺ) said:
حَدَّثَنَا أَبُو كُرَيْبٍ، مُحَمَّدُ بْنُ الْعَلاَءِ حَدَّثَنَا أَبُو أُسَامَةَ ، حَدَّثَنَا بُرَيْدٌ ، عَنْ أَبِي بُرْدَةَ ، عَنْ أَبِي مُوسَى ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنِّي لأَعْرِفُ أَصْوَاتَ رُفْقَةِ الأَشْعَرِيِّينَ بِالْقُرْآنِ حِينَ يَدْخُلُونَ بِاللَّيْلِ وَأَعْرِفُ مَنَازِلَهُمْ مِنْ أَصْوَاتِهِمْ بِالْقُرْآنِ بِاللَّيْلِ وَإِنْ كُنْتُ لَمْ أَرَ مَنَازِلَهُمْ حِينَ نَزَلُوا بِالنَّهَارِ وَمِنْهُمْ حَكِيمٌ إِذَا لَقِيَ الْخَيْلَ - أَوْ قَالَ الْعَدُوَّ - قَالَ لَهُمْ إِنَّ أَصْحَابِي يَأْمُرُونَكُمْ أَنْ تَنْظُرُوهُمْ " .
I recognise the voice of the Ash'arites while they recite the Qur'an as they arrive during the night and I also recognise their station from the recital of the Qur'an during the night time, although I have not seen their encampments as they encamp during the day time. And there is a person amongst them, Hakim; when he encounters the horsemen or the enemies he says to them: My friends command you to wait for them.