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 factions among the believers should fight, then make settlement between the two. But if one of them oppresses the other, then fight against the one that oppresses until it returns to the ordinance of Allāh. And if it returns, then make settlement between them in justice and act justly. Indeed, Allāh loves those who act justly.”

Al-Hujuraat 49:9 · Saheeh International