Qur'ān 22:39 · Al-Hajj (الحج)

أُذِنَ لِلَّذِينَ يُقَـٰتَلُونَ بِأَنَّهُمْ ظُلِمُوا۟ ۚ وَإِنَّ ٱللَّهَ عَلَىٰ نَصْرِهِمْ لَقَدِيرٌ

Permission [to fight] has been given to those who are being fought, because they were wronged. And indeed, Allah is competent to give them victory.