[Machine] It is said that Anas ibn Malik heard that a group of young Ansar would listen to the Quran, then go to a corner of the city where their families would think they were in the mosque, while the people of the mosque would think they were with their families. They would pray during the night until dawn approached, some of them would gather firewood and others would fetch fresh water, and then they would head towards the doors of the Prophet's Mosque. The Prophet sent them to the well of Ma'unah, where they were martyred. The Prophet then prayed for those who killed them for fifteen nights, and so on.  

أَنَّهُ سَمِعَ أَنَسَ بْنَ مَالِكٍ ؓ يَقُولُ كَانَ شَبَابٌ مِنَ الْأَنْصَارِ يَسْتَمِعُونَ الْقُرْآنَ ثُمَّ يَتَنَحَّوْنَ فِي نَاحِيَةِ الْمَدِينَةِ يَحْسَبُ أَهْلُوهُمْ أَنَّهُمْ فِي الْمَسْجِدِ وَيَحْسَبُ أَهْلُ الْمَسْجِدِ أَنَّهُمْ فِي أَهْلِيهِمْ فَيُصَلُّونَ مِنَ اللَّيْلِ حَتَّى إِذَا تَقَارَبَ الصُّبْحُ احْتَطَبَ بَعْضُهُمْ وَاسْتَقَى بَعْضُهُمْ مِنَ الْمَاءِ الْعَذْبِ ثُمَّ يُقْبِلُونَ حَتَّى يَضَعُوا حِزَمَهُمْ وَقِرَبَهُمْ عَلَى أَبْوَابِ حُجَرِ النَّبِيِّ ﷺ فَبَعَثَهُمُ النَّبِيُّ ﷺ إِلَى بِئْرِ مَعُونَةَ فَاسْتُشْهِدُوا كُلُّهُمْ فَدَعَا رَسُولُ اللهِ ﷺ عَلَى مَنْ قَتَلَهُمْ خَمْسَ عَشْرَةَ لَيْلَةً وَكَذَلِكَ