The scholars say: the fighting that takes place between these two groups is not intentional in reality; therefore, it does not prevent mutual inheritance. It has already been mentioned in the Book of Inheritance that if the just party kills the rebel, or the rebel kills the just party, they inherit from one another.
Some scholars hold that if the killer is from the just party, he inherits from the rebel; but if the killer is from the rebel party, he does not inherit from the just party. This is because the fighting of the just party is lawful, whereas the fighting of the rebel party is unlawful. We have previously stated that this is a very strong view. The position of the madhhab, however, is that each inherits from the other, because this is fighting based on an interpretation.
If two groups fight one another out of tribal partisanship or for leadership, then both are wrongdoers, and each is liable for what it destroys of the other’s property.
The author’s statement, “If two groups fight one another out of tribal partisanship or for leadership, then both are wrongdoers”: If two groups of believers fight one another out of tribal partisanship or for leadership, the difference between the two is that tribal partisanship arises from mutual boasting. Neither side seeks to dominate the other, but they quarrel among themselves, and each group says to the other, “You are such-and-such a tribe, and you have this and that fault.” The matter then becomes inflamed between the two groups, and they fight one another.
As for leadership, each group seeks leadership over the other; that is, they want to overwhelm them and incorporate them into their own side. Both groups are wrongdoers. But do they thereby disbelieve? No, for fighting a believer is not disbelief that takes one outside the fold of Islam; likewise, killing him is not disbelief that takes one outside the fold of Islam. What, then, should we do? Allah, the Exalted, says:
“And if two groups of the believers fight one another, then make peace between them. But if one of them transgresses against the other, then fight the one that transgresses until it returns to the command of Allah. If it returns, then make peace between them with justice and act equitably. Surely Allah loves those who are equitable. The believers are but brothers, so make peace between your two brothers.” [al-Hujurat: 9–10]