Some people refute the authentic hadith, "When two Muslims face each other with their swords, both the killer and the killed are in the Fire," by saying that the Companions fought each other after the Messenger of Allah (peace and blessings be upon him)

The questioner : The question is: Some people refute the authentic hadith with the following argument: The Companions fought each other after the Messenger of Allah (peace and blessings be upon him), and some of them were among those promised Paradise. How do you reconcile the hadith with the fighting among some of the Companions during the time of 'Ali (may Allah be pleased with him)?

The Shaykh : The hadith is to be understood as applying to those who fight each other not in the cause of Allah, but in the cause of vindicating oneself, or being greedy for wealth, or the like. It is necessary to interpret the hadith this way. The question arises in reality because the questioner, at least, does not remember, and I do not say he is unaware of, the saying of Allah the Exalted: . We find in this verse an explicit statement from the Lord of the Worlds (Mighty and Majestic) applying the term "believers" to both the righteous party and the transgressing party: . So when our Lord (Mighty and Majestic) rules that both of the two fighting parties are among the believers, then we cannot reconcile the verse with this hadith except by interpreting the hadith as referring to fighting in the cause of worldly matters, not in the cause of seeking the truth, as is the intent of the previous verse. In this case, both are in the Fire because each intended to kill the other without right. However, when each fights the other in what he believes is the cause of Allah, this hadith does not apply to such a situation; rather, the verse applies to this situation. In that case, the hadith must be interpreted as referring to fighting in the cause of worldly matters. Both of these situations exist on this earth: 'Ali's fighting with Mu'awiyah, 'Ali's fighting with the army of 'Aishah, and the like, all fall under the general scope of the verse , etc. This is what we say to reconcile the verse and the hadith. However, in any believing party, we can imagine that there may be individuals who are not believers at all, but rather they displayed Islam outwardly while concealing disbelief inwardly. They appeared as Muslims, but in themselves, legally, they are hypocrites, as Allah the Exalted said: . As for the two fighting armies, the army of 'Ali and the army of Mu'awiyah, I personally do not find it strange that there may be individuals in both armies to whom the verse does not apply, but to whom the hadith does apply. That is, individuals who took it up out of pre-Islamic tribal loyalty in both parties, while the majority is considered to have fought, some of them fighting others, in the cause of establishing the truth that they believe in. In conclusion, the hadith applies to those whose intention was bad, and the verse applies to those whose intention was good, but who may have been mistaken and not correct in their action.
This reminds me to clarify for you the meaning of another hadith, which is famous and authentic, and many people are often tested by it through its misapplication or misunderstanding. It is his saying (peace and blessings be upon him): . And whoever says to a Muslim, "You are a disbeliever," . This hadith also must be interpreted and explained as the hadith of the fighting Muslims was explained, namely that both are in the Fire due to their bad intentions, unlike if their intentions were good. So whoever declares a Muslim a disbeliever has committed disbelief, if he declares him a disbeliever while knowing that he is not a disbeliever, knowing that he is a Muslim, and then pronounces the ruling of disbelief upon him; this disbelief returns to him. But if he declares him a disbeliever based on what he heard from him or what appeared to him, and he did not rush, did not vindicate himself, and did not follow his desires, then this hadith does not apply to him, even if he declared him a disbeliever while being mistaken, as long as he did not intend to declare him a disbeliever in his heart, but rather intended to pronounce the ruling that he deserves legally, but in the end, he was mistaken. This is how hadiths must be interpreted in light of other hadiths and legal principles. This also reminds us of a very important reality from which people have strayed, both in the past and the present, and they have deviated from the path of the Muslim community.
It reminds us that disbelief is of two types: disbelief of the heart and practical disbelief. Disbelief of the heart is what takes its owner out of the religion, while practical disbelief does not take him out of the religion. Accordingly, hadiths should also be interpreted, including his saying (peace and blessings be upon him): . Is the mere fighting of a Muslim against his Muslim brother disbelief? Does it mean apostasy? The answer is: We look at his fighting against his Muslim brother. If it is accompanied by a heart that considers this fighting lawful, i.e., fighting a Muslim, then it is doctrinal disbelief, and it means apostasy. But if his fighting against his Muslim brother is not accompanied by considering this fighting lawful in his heart, but is rather a sin among his sins against his Lord, then it is practical disbelief, not doctrinal disbelief. This is a topic we have discussed repeatedly and over and over.