Hadith 21:199
It was narrated that Hisham bin 'Amir said:
"On the day of Uhud the people were exhausted. The Prophet said: 'Dig graves and make them wide, and bury two or three in a grave.' They said: 'O Messenger of Allah, who should we 'put in first? He said: 'Put in first the one who knew the Qur'an most."'
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ الْمُبَارَكِ، قَالَ حَدَّثَنَا وَكِيعٌ، عَنْ سُلَيْمَانَ بْنِ الْمُغِيرَةِ، عَنْ حُمَيْدِ بْنِ هِلاَلٍ، عَنْ هِشَامِ بْنِ عَامِرٍ، قَالَ : لَمَّا كَانَ يَوْمُ أُحُدٍ أَصَابَ النَّاسَ جَهْدٌ شَدِيدٌ، فَقَالَ النَّبِيُّ صلى الله عليه وسلم : " احْفِرُوا وَأَوْسِعُوا، وَادْفِنُوا الاِثْنَيْنِ وَالثَّلاَثَةَ فِي قَبْرٍ " . فَقَالُوا : يَا رَسُولَ اللَّهِ فَمَنْ نُقَدِّمُ قَالَ : " قَدِّمُوا أَكْثَرَهُمْ قُرْآنًا "
Original Reference: Sunan an-Nasa'i 2015