Anas bin Malik reported,

I grieved deeply for those who were killed at the battle of Harrah. Zayd bin Arqam wrote to me when news reached him of the intensity of my grief, mentioning that he had heard the Messenger of Allah ﷺ say, "O Allah, forgive the Ansar, and the sons of the Ansar." Ibn Fadl was uncertain whether it also included "the sons of the sons of the Ansar."Someone present asked Anas about him, and he replied, "He is the one about whom the Messenger of Allah ﷺ said, 'This is the one whose ear Allah confirmed as truthful.'"

Bukhari 4906

Sahih

حدثنا إسماعيل بن عبد الله قال حدثني إسماعيل بن إبراهيم بن عقبة عن موسى بن عقبة قال حدثني عبد الله بن الفضل أنه سمع

أنس بن مالك يقول

حزنت على من أصيب بالحرة فكتب إلي زيد بن أرقم وبلغه شدة حزني يذكر أنه سمع رسول الله ﷺ يقول اللهم اغفر للأنصار ولأبناء الأنصار وشك ابن الفضل في أبناء أبناء الأنصار فسأل أنسا بعض من كان عنده فقال هو الذي يقول رسول الله ﷺ هذا الذي أوفى الله له بأذنه

البخاري 4906صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Tafsir
Chapter
His saying, "They are the ones who say, 'Do not spend on those who are with the Messenger of Allah until they disperse'" and scatter
Numbering
Darussalam 4906
Bukhari 4906