Sahih al-Bukhari, Volume 9, Book 84, Hadith 65 (USC-MSA) ⓘ

Narrated `Abdullah bin `Amr bin Yasar: That they visited Abu Sa`id Al-Khudri and asked him about Al-Harauriyya, a special unorthodox religious sect, "Did you hear the Prophet saying anything about them?" Abu Sa`id said, "I do not know what Al-Harauriyya is, but I heard the Prophet saying, "There will appear in this nation---- he did not say: From this nation ---- a group of people so pious apparently that you will consider your prayers inferior to their prayers, but they will recite the Qur'an, the teachings of which will not go beyond their throats and will go out of their religion as an arrow darts through the game, whereupon the archer may look at his arrow, its Nasl at its Risaf and its Fuqa to see whether it is blood-stained or not (i.e. they will have not even a trace of Islam in them).

حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا عَبْدُ الْوَهَّابِ، قَالَ سَمِعْتُ يَحْيَى بْنَ سَعِيدٍ، قَالَ أَخْبَرَنِي مُحَمَّدُ بْنُ إِبْرَاهِيمَ، عَنْ أَبِي سَلَمَةَ، وَعَطَاءِ بْنِ يَسَارٍ، أَنَّهُمَا أَتَيَا أَبَا سَعِيدٍ الْخُدْرِيَّ فَسَأَلاَهُ عَنِ الْحَرُورِيَّةِ، أَسَمِعْتَ النَّبِيَّ صلى الله عليه وسلم‏.‏ قَالَ لاَ أَدْرِي مَا الْحَرُورِيَّةُ سَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَقُولُ ‏ "‏ يَخْرُجُ فِي هَذِهِ الأُمَّةِ ـ وَلَمْ يَقُلْ مِنْهَا ـ قَوْمٌ تَحْقِرُونَ صَلاَتَكُمْ مَعَ صَلاَتِهِمْ، يَقْرَءُونَ الْقُرْآنَ لاَ يُجَاوِزُ حُلُوقَهُمْ ـ أَوْ حَنَاجِرَهُمْ ـ يَمْرُقُونَ مِنَ الدِّينِ مُرُوقَ السَّهْمِ مِنَ الرَّمِيَّةِ، فَيَنْظُرُ الرَّامِي إِلَى سَهْمِهِ إِلَى نَصْلِهِ إِلَى رِصَافِهِ، فَيَتَمَارَى فِي الْفُوقَةِ، هَلْ عَلِقَ بِهَا مِنَ الدَّمِ شَىْءٌ ‏" ‏‏.‏