Qur'an 49:9

وَإِن طَآئِفَتَانِ مِنَ ٱلْمُؤْمِنِينَ ٱقْتَتَلُوا۟ فَأَصْلِحُوا۟ بَيْنَهُمَا ۖ فَإِنۢ بَغَتْ إِحْدَىٰهُمَا عَلَى ٱلْأُخْرَىٰ فَقَـٰتِلُوا۟ ٱلَّتِى تَبْغِى حَتَّىٰ تَفِىٓءَ إِلَىٰٓ أَمْرِ ٱللَّهِ ۚ فَإِن فَآءَتْ فَأَصْلِحُوا۟ بَيْنَهُمَا بِٱلْعَدْلِ وَأَقْسِطُوٓا۟ ۖ إِنَّ ٱللَّهَ يُحِبُّ ٱلْمُقْسِطِينَ

And if two parties of believers fall to fighting, then make peace between them. And if one party of them doeth wrong to the other, fight ye that which doeth wrong till it return unto the ordinance of Allah; then, if it return, make peace between them justly, and act equitably. Lo! Allah loveth the equitable.