Surah Al-Hajj — Ayah 39 (22:39)
أُذِنَ لِلَّذِينَ يُقَٰتَلُونَ بِأَنَّهُمۡ ظُلِمُواْۚ وَإِنَّ ٱللَّهَ عَلَىٰ نَصۡرِهِمۡ لَقَدِيرٌ ٣٩
English translation (Saheeh International)
Permission [to fight] has been given to those who are being fought,1 because they were wronged. And indeed, Allāh is competent to give them victory.
- - Referring here to the Prophet's companions.
Brief commentary
Allah has given permission to fight to the believers who are fought by the idolaters, due to their being oppressed by their enemies. Allah has the power to help the believers against their enemies without fighting. However, the wisdom of Allah required that the believers be tested through fighting the disbelievers.