صحيح البخاري Sahih Bukhari كتاب الجنائز The Book of Al-Janaiz (Funerals)
بَابُ مَنْ يُقَدَّمُ فِي اللَّحْدِ:

(75) Chapter. Who should be put first in the Lahd (a side extension of a grave) and it is called Lahd because it is to the side. If it is a straight one (i.e. has no side extension), it is called Darih.

2 hadith
Hadith 1347
حَدَّثَنَا مُحَمَّدُ بْنُ مُقَاتِلٍ ، أَخْبَرَنَا عَبْدُ اللَّهِ ، أَخْبَرَنَا لَيْثُ بْنُ سَعْدٍ ، حَدَّثَنِي ابْنُ شِهَابٍ ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ كَعْبِ بْنِ مَالِكٍ ، عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ رَضِيَ اللَّهُ عَنْهُمَا ، " أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ يَجْمَعُ بَيْنَ الرَّجُلَيْنِ مِنْ قَتْلَى أُحُدٍ فِي ثَوْبٍ وَاحِدٍ ، ثُمَّ يَقُولُ : أَيُّهُمْ أَكْثَرُ أَخْذًا لِلْقُرْآنِ ؟ ، فَإِذَا أُشِيرَ لَهُ إِلَى أَحَدِهِمَا قَدَّمَهُ فِي اللَّحْدِ , وَقَالَ : أَنَا شَهِيدٌ عَلَى هَؤُلَاءِ ، وَأَمَرَ بِدَفْنِهِمْ بِدِمَائِهِمْ ، وَلَمْ يُصَلِّ عَلَيْهِمْ ، وَلَمْ يُغَسِّلْهُمْ " .
Narrated Jabir bin `Abdullah: Allah's Apostle shrouded every two martyrs of Uhud in one piece of cloth and then he would ask, "Which of them knew more Qur'an?" When one of them was pointed out he would put him first in the grave. He said, "I am a witness on these." Then he ordered them to be buried with blood on their bodies. Neither did he offer their funeral prayer nor did he get them washed.
Hadith Reference Sahih Bukhari / The Book of Al-Janaiz (Funerals) / Hadith: 1347
Hadith Grading محدثین: أحاديث صحيح البخاريّ كلّها صحيحة
Hadith 1348
أَخْبَرَنَا الْأَوْزَاعِيُّ ، عَنِ الزُّهْرِيِّ ، عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ رَضِيَ اللَّهُ عَنْهُمَا ، كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ لِقَتْلَى أُحُدٍ : أَيُّ هَؤُلَاءِ أَكْثَرُ أَخْذًا لِلْقُرْآنِ ؟ , فَإِذَا أُشِيرَ لَهُ إِلَى رَجُلٍ قَدَّمَهُ فِي اللَّحْدِ قَبْلَ صَاحِبِهِ ، وَقَالَ جَابِرٌ : فَكُفِّنَ أَبِي وَعَمِّي فِي نَمِرَةٍ وَاحِدَةٍ .
(Jabir bin `Abdullah added): Allah's Apostle used to ask about the martyrs of Uhud as to which of them knew more of the Qur'an." And when one of them was pointed out as having more of it he would put him first in the grave and then his companions. (Jabir added): My father and my uncle were shrouded in one sheet.
Hadith Reference Sahih Bukhari / The Book of Al-Janaiz (Funerals) / Hadith: 1348
Hadith Grading محدثین: أحاديث صحيح البخاريّ كلّها صحيحة