"We know of no Arab tribe with more martyrs, or who will be more honored on the Day of Resurrection, than the Ansar."Qatada said, Anas bin Malik told us that seventy of them were killed on the day of Uhud, seventy at Bir Maunah, and seventy on the day of Yamamah.He said, Bir Maunah took place during the lifetime of the Messenger of Allah ﷺ, while the day of Yamamah occurred during the caliphate of Abu Bakr al-Siddiq, on the day of Musaylimah the Liar.
ما نعلم حيا من أحياء العرب أكثر شهيدا، أعز يوم القيامة من الأنصار. قال قتادة: وحدثنا أنس بن مالك أنه قتل منهم يوم أحد سبعون، ويوم بئر معونة سبعون، ويوم اليمامة سبعون. قال: وكان بئر معونة على عهد رسول الله ﷺ، ويوم اليمامة على عهد أبي بكر الصديق يوم مسيلمة الكذاب.
Bukhari narrated it in Maghazi (4078) from Amr bin Ali, [who said], Muaz bin Hisham narrated to us, he said, my father narrated to me, from Qatada, and he mentioned it.But Ibn Ishaq said, "All those martyred among the Muslims with the Messenger of Allah ﷺ from the Migrants and the Helpers were sixty-five men."I say, four more of the Migrants are not included among them either, namely Hamza, Abdullah bin Jahsh, Musab bin Umayr, and Shammas bin Uthman, while the rest were from the Helpers. Ibn Hisham supplemented what Ibn Ishaq had mentioned with five more, bringing the total to seventy. Ibn Ishaq listed their names, as well as the names of those killed among the polytheists, who numbered twenty-two men.Sirat bin Hisham (2/122-127)