An Nahl, 126 Ayah
16:126
وَإِنۡ عَاقَبۡتُمۡ فَعَاقِبُواْ بِمِثۡلِ مَا عُوقِبۡتُم بِهِۦۖ وَلَئِن صَبَرۡتُمۡ لَهُوَ خَيۡرٞ لِّلصَّٰبِرِينَ ١٢٦
Wa 'In `Āqabtum Fa`āqibū Bimithli Mā `Ūqibtum Bihi ۖ Wa La'in Şabartum Lahuwa Khayrun Lilşşābirīna
And if you punish [an enemy, O believers], punish with an equivalent of that with which you were harmed. But if you are patient - it is better for those who are patient.