Narrated Qatada
We do not know of any tribe amongst the 'Arab tribes who lost more martyrs than Al-Ansar, and they will have superiority on the Day of Resurrection. Anas bin Malik told us that seventy from the Ansar were martyred on the day of Uhud, and seventy on the day (of the battle of) Bir Ma'una, and seventy on the day of Al-Yamama. Anas added, "The battle of Bir Ma'una took place during the lifetime of Allah's Messenger (ﷺ) and the battle of Al-Yamama, during the caliphate of Abu Bakr, and it was the day when Musailamah Al-Kadhdhab was killed."
Narrated Jabir bin `Abdullah
Allah's Messenger (ﷺ) used to shroud two martyrs of Uhud in one sheet and then say, "Which of them knew Qur'an more?" When one of the two was pointed out, he would put him first in the grave. Then he said, "I will be a witness for them on the Day of Resurrection." He ordered them to be buried with their blood (on their bodies). Neither was the funeral prayer offered for them, nor were they washed. Jabir added, "When my father was martyred, I started weeping and uncovering his face. The companions of the Prophet (ﷺ) stopped me from doing so but the Prophet (ﷺ) did not stop me. Then the Prophet said, '(O Jabir.) don't weep over him, for the angels kept on covering him with their wings till his body was carried away (for burial).
Narrated Abu Musa
The Prophet (ﷺ) said, "I saw in a dream that I moved a sword and its blade got broken, and that symbolized the casualties which the believers suffered on the day of Uhud. Then I moved it again, and it became as perfect as it had been, and that symbolized the Conquest (of Mecca) which Allah helped us to achieve, and the union of all the believers. I (also) saw cows in the dream, and what Allah does is always beneficial. Those cows appeared to symbolize the faithful believers (who were martyred) on the day of Uhud."
Narrated Khabbab
We migrated with the Prophet (ﷺ) for Allah's Cause, so our reward became due with Allah. Some of us passed away (i.e. died) without enjoying anything from their reward, and one of them was Mus`ab bin `Umar who was killed (i.e. martyred) on the day of Uhud. He did not leave behind except a sheet of striped woolen cloth. If we covered his head with it, his feet became naked, and if we covered his feet with it, his head became naked. The Prophet (ﷺ) said to us, "Cover his head with it and put Idhkhir (i.e. a kind of grass) over his feet," or said, "Put some Idhkhir over his feet." But some of us have got their fruits ripened, and they are collecting them.