Al-Hajj - 22:60

ذَلِكَ وَمَنْ عَاقَبَ بِمِثْلِ مَا عُوقِبَ بِهِ ثُمَّ بُغِيَ عَلَيْهِ لَيَنصُرَنَّهُ اللَّهُ إِنَّ اللَّهَ لَعَفُوٌّ غَفُورٌ
[22:60]
That (shall be so); and he who retaliates with the like of that with which he has been afflicted and he has been oppressed, Allah will most certainly aid him; most surely Allah is Pardoning, Forgiving.
That (is so). And if one has retaliated to no greater extent than the injury he received, and is again set upon inordinately, Allah will help him: for Allah is One that blots out (sins) and forgives (again and again).
That (is so). And whoso hath retaliated with the like of that which he was made to suffer and then hath (again) been wronged, Allah will succour him. Lo! Allah verily is Mild, Forgiving.