The first verse revealed concerning fighting, as Urwa informed me on the authority of Ayesha, was "Permission has been given to those who are being fought, because they were wronged. And indeed, Allah is competent to give them victory" [Hajj 22:39] up to His saying "Indeed, Allah is Powerful and Exalted in Might" [Hajj 22:40]. Then permission for fighting was given in many verses of the Quran.
فكان أول آية نزلت في القتال كما أخبرني عروة، عن عائشة: {أذن للذين يقتلون بأنهم ظلموا وإن الله على نصرهم لقدير} إلى قوله تعالى: {إن الله لقوي عزيز} [سورة الحج: ٣٩-٤٠] ثم أذن بالقتال في آي كثير من القرآن.
Nasai narrated it in Al-Kubra (11283), from Zakariya bin Yahya, who said, Muhammad bin Yahya narrated to us, who said, Muhammad bin Abdul-Aziz bin Abu Razmah narrated to us, who said, Salmuwayh Abu Salih narrated to us, who said, Abdullah informed us, from Yunus, from Zuhri, who mentioned it.Ibn Hajar said in Fath al-Bari (7/280), "Its chain of transmission is sahih." Abdullah here is Ibn Mubarak, and the narrator from him, Salmuwayh, is Sulayman bin Salih Al-Laythi, Salmuwayh being his title, and he is among the men of the Sahih.