He heard Anas bin Malik say, "I grieved deeply for those killed at the Battle of Harrah. Zayd bin Arqam wrote to me when news reached him of the intensity of my sorrow, mentioning that he had heard the Messenger of Allah ﷺ say, 'O Allah, forgive the Ansar, and the sons of the Ansar,'" and Ibn Fadl was uncertain whether he also said, "and the sons of the sons of the Ansar."One of those present asked Anas about Zayd, 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.'"
أنه سمع أنس بن مالك يقول: حزنت على من أصيب بالحرة، فكتب إلي زيد بن الأرقم 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.
Bukhari narrated it in the Tafsir (4906) from Ismail bin Abdullah, who said, Ismail bin Ibrahim bin Uqba narrated to me, from Musa bin Uqba, who said, Abdullah bin Fadl narrated to me that he heard Anas bin Malik say, and he mentioned it.Muslim narrated it in the Virtues of the Companions (2506) through several chains from Shuba, from Qatada, from Nadr bin Anas, from Zayd bin Arqam, who said, the Messenger of Allah ﷺ said, "O Allah, forgive the Ansar, and the sons of the Ansar, and the sons of the sons of the Ansar."