Al-Hujurat 49:9

Wa-in ta-ifatani minaalmu/mineena iqtataloo faaslihoo baynahumafa-in baghat ihdahuma AAala al-okhrafaqatiloo allatee tabghee hatta tafee-a ilaamri Allahi fa-in faat faaslihoobaynahuma bilAAadli waaqsitoo inna Allahayuhibbu almuqsiteen

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.

If two groups of the believers fight each other, seek reconciliation between them. And if one of them commits aggression against the other, fight the one that commits aggression until it comes back to Allah’s command. So if it comes back, seek reconciliation between them with fairness, and maintain justice. Surely Allah loves those who maintain justice.