Sunan an-Nasa'i, Volume 3, Book 21, Hadith 1957 (DarusSalam) ⓘ

It was narrated from 'Abdur-Rahman bin Ka 'b bin Malik that Jabir bin 'Abdullah told him that: the Messenger of Allah put two men from those who had been slain in Uhud in one shrud, then he would ask which of them had learned more Qur'an and when one of them was pointed out, he would put him in the Lahd (grave) first. He said: "I am a witness to these." And he ordered that they be buried with their blood, and that the funeral prayer should not be offered, and they should not be washed.

أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنِ ابْنِ شِهَابٍ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ كَعْبِ بْنِ مَالِكٍ، أَنَّ جَابِرَ بْنَ عَبْدِ اللَّهِ، أَخْبَرَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَجْمَعُ بَيْنَ الرَّجُلَيْنِ مِنْ قَتْلَى أُحُدٍ فِي ثَوْبٍ وَاحِدٍ ثُمَّ يَقُولُ ‏"‏ أَيُّهُمَا أَكْثَرُ أَخْذًا لِلْقُرْآنِ ‏"‏ ‏.‏ فَإِذَا أُشِيرَ إِلَى أَحَدِهِمَا قَدَّمَهُ فِي اللَّحْدِ ‏.‏ قَالَ ‏"‏ أَنَا شَهِيدٌ عَلَى هَؤُلاَءِ ‏"‏ ‏.‏ وَأَمَرَ بِدَفْنِهِمْ فِي دِمَائِهِمْ وَلَمْ يُصَلِّ عَلَيْهِمْ وَلَمْ يُغَسَّلُوا ‏.‏