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.
O believers! If two groups of believers quarrel with one another, then reconcile between them by inviting them to let the law of Allah be the judgement between them. Then, if one of the two reject the reconciliation and transgresses, fight the transgressing group until it returns to accepting the command of Allah. If it returns, reconcile between the two groups with fairness and justice. And be fair in your judgement between them, indeed, Allah loves those who are fair in their judgement.