I said to Ibn Abbas, "Surah at-Tawba?"He replied, "At-Tawba is the exposer. It kept on being revealed with 'and among them... and among them...' until they thought it would not leave anyone among them without mentioning him."I asked, "Surah al-Anfal?"He said, "It was revealed concerning Badr."I asked, "Surah al-Hashr?"He said, "It was revealed concerning Banu an-Nadir."
قلت لابن عباس: سورة التوبة؟ قال: التوبة هي الفاضحة، ما زالت تنزل: ومنهم ومنهم حتى ظنوا أنها لم تبق أحدا منهم إلا ذكر فيها. قال: قلت: سورة الأنفال؟ قال: نزلت في بدر. قال: قلت: سورة الحشر؟ قال: نزلت في بني النضير.
Bukhari narrated it in the tafsir (4882) and Muslim in the tafsir (3031:31), both through Hushaym, who said, Abu Bishr (that is, Jafar bin Abu Wahshiya) informed us, from Saeed bin Jubayr, who said, then he mentioned it.