It was narrated that Hisham bin 'Amir said:

"We complained to the Messenger of Allah on the day of Uhud, saying: 'O Messneger of Allah, it is too difficult for us to dig a grave for each person.' The Messenger of Allah said: 'Dig graves and make them good and deep, and bury two or three in one grave.' They said: 'Who should we put in first, O Messenger of Allah?' He said: 'Put in first the one who knew more Qur'an."' He said: "My father was the third of three in one grave."

أَخْبَرَنَا مُحَمَّدُ بْنُ بَشَّارٍ، قَالَ حَدَّثَنَا إِسْحَاقُ بْنُ يُوسُفَ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ أَيُّوبَ، عَنْ حُمَيْدِ بْنِ هِلاَلٍ، عَنْ هِشَامِ بْنِ عَامِرٍ، قَالَ : شَكَوْنَا إِلَى رَسُولِ اللَّهِ ﷺ يَوْمَ أُحُدٍ فَقُلْنَا : يَا رَسُولَ اللَّهِ الْحَفْرُ عَلَيْنَا لِكُلِّ إِنْسَانٍ شَدِيدٌ فَقَالَ رَسُولُ اللَّهِ ﷺ : " احْفِرُوا وَأَعْمِقُوا وَأَحْسِنُوا، وَادْفِنُوا الاِثْنَيْنِ وَالثَّلاَثَةَ فِي قَبْرٍ وَاحِدٍ " . قَالُوا : فَمَنْ نُقَدِّمُ يَا رَسُولَ اللَّهِ قَالَ : " قَدِّمُوا أَكْثَرَهُمْ قُرْآنًا " . قَالَ : فَكَانَ أَبِي ثَالِثَ ثَلاَثَةٍ فِي قَبْرٍ وَاحِدٍ .