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."
Sahih al-Bukhari Book 64, Hadith 123
← Previous Hadith Regarding the Holy Verse: "Those who responded (To the call) of Allah And the Apostle (Muhammad), After being wounded, For those of them Who did good deeds And refrained from wrong, there is a great reward." (3.172) She said to `Urwa, "O my nephew! Your father, Az-Zubair and Abu Bakr were amongst them (i.e. those who responded to the call of Allah and the Apostle on the day (of the battle of Uhud). When Allah's Messenger (ﷺ), suffered what he suffered on the day of Uhud and the pagans left, the Prophet (ﷺ) was afraid that they might return. So he said, 'Who will go on their (i.e. pagans') track?' He then selected seventy men from amongst them (for this purpose)." (The sub-narrator added, "Abu Bakr and Az- Zubair were amongst them.")

Sahih al-Bukhari Book 64, Hadith 122 Next Hadith → 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).

Sahih al-Bukhari Book 64, Hadith 124