The Prophet ﷺ collected every two martyrs of Uhud in one piece of cloth, then he would ask, "Which of them had (knew) more of the Qur'an?" When one of them was pointed out for him, he would put that one first in the grave and say, "I will be a witness on these on the Day of Resurrection." He ordered them to be buried with their blood on their bodies and they were neither washed nor was a funeral prayer offered for them.  

كَانَ النَّبِيُّ ﷺ 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 هَؤُلاَءِ يَوْمَ الْقِيَامَةِ وَأَمَرَ بِدَفْنِهِمْ فِي دِمَائِهِمْ وَلَمْ يُغَسَّلُوا وَلَمْ يُصَلَّ عَلَيْهِمْ  

One day the Prophet ﷺ went out and offered the funeral prayers of the martyrs of Uhud and then went up the pulpit and said, "I will pave the way for you as your predecessor and will be a witness on you. By Allah! I see my Fount (Kauthar) just now and I have been given the keys of all the treasures of the earth (or the keys of the earth). By Allah! I am not afraid that you will worship others along with Allah after my death, but I am afraid that you will fight with one another for the worldly things."  

أَنَّ النَّبِيَّ ﷺ خَرَجَ يَوْمًا فَصَلَّى عَلَى أَهْلِ أُحُدٍ صَلاَتَهُ عَلَى الْمَيِّتِ ثُمَّ انْصَرَفَ إِلَى الْمِنْبَرِ فَقَالَ إِنِّي فَرَطٌ لَكُمْ وَأَنَا شَهِيدٌ عَلَيْكُمْ وَإِنِّي وَاللَّهِ لأَنْظُرُ إِلَى حَوْضِي الآنَ وَإِنِّي أُعْطِيتُ مَفَاتِيحَ خَزَائِنِ الأَرْضِ أَوْ مَفَاتِيحَ الأَرْضِ وَإِنِّي وَاللَّهِ مَا أَخَافُ عَلَيْكُمْ أَنْ تُشْرِكُوا بَعْدِي وَلَكِنْ أَخَافُ عَلَيْكُمْ أَنْ تَنَافَسُوا فِيهَا