The Women - 4:75
"What has happened to you that you do not fight in the way of Allah, despite the oppressed men, women and children who cry out, "Our Lord, deliver us from this land whose people are oppressors, protect us, help us"?"
Related:
The Repentance/9:38
"O you who believe, what has happened to you that when you were told, "Take action in the way of Allah,"you fell to the ground? Are you content with the life of this world instead of the Hereafter? The blessings of the life of this world are little compared to the life of the Hereafter."
Council/42:42
But those who oppress the people and those who attack unjustly in the land should be opposed. For them is a painful torment.