Whoever unjustly quarrels with or holds grudges against their fellow Muslim: The sin of such quarreling will not be forgiven until they reconcile with the other person, as this falls under the rights of Allah's servants that can only be forgiven through mutual pardoning. As for their other sins: These may be forgiven through sincere repentance or by the Mercy of Allah, the Most Merciful. This is true even while they remain in conflict with their fellow Muslim. However, they should fear being deprived of complete forgiveness or being unable to achieve sincere repentance. Therefore, those who harbor grudges should be wary of their condition and hasten to make peace with others.