Ibn Shihab Zuhri reported,

The first verse revealed concerning fighting, as Urwa informed me on the authority of Ayesha, was "Permission is given to those who are being fought because they have been wronged, and indeed Allah is fully capable of granting them victory" up to His saying "Indeed Allah is Strong and Mighty" [Hajj 22:39–40]. Then permission to fight was given in many verses of the Quran.

Azami 12807

Sahih

عن ابن شهاب الزهري قال

فكان أول آية نزلت في القتال، كما أخبرني عروة، عن عائشة: {أذن للذين يقتلون بأنهم ظلموا وإن الله على نصرهم لقدير} إلى قوله {إن الله لقوي عزيز} ثم أذن بالقتال في آي كثير من القرآن.

الأعظمي 12807صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Tafsir of the great Quran
Chapter
Tafsir of Surah Anbiya
Section
His saying, "Permission has been granted to those who are being fought because they were wronged, and indeed Allah is able to give them victory. Those who have been expelled from their homes unjustly, only because they say our Lord is Allah. And were it not that Allah checks the people, some by means of others, there would have been demolished monasteries, churches, synagogues, and mosques in which the name of Allah is much mentioned. And Allah will surely support those who support Him. Indeed Allah is Powerful, Exalted in Might."
Numbering
Jami al-Kamil 12807 (2nd edition)
Azami 12807