Blade
All the Sunni Hadiths were written by those who were deeply sympathetic to Aisha, Muawiya and Yazid and you won’t find any Hadiths critical of their actions. Check the Shi’a Hadiths.
I'm not Shia. The whole shia ideology to me is wrong and shameless.
Abu Bakrah ath-Thaqafi (may Allāh be pleased with him) reported – The Prophet
said “If two Muslims meet each other with their swords, then both the killer and the killed will be in the Hell-fire.” I said, “O Allāh’s Messenger, that is the case for the killer but why should that be the case for the killed?” He answered, “Because he wanted to kill his companion.” [Al-Bukhari & Muslim]
Shaykh Ibn Uthaymeen (may Allāh have mercy on him), in his explanation of this hadith says that the condition of the sentence “When two Muslims meet with their swords” does not exclusively refer to a sword; the term applies to any weapon with which two Muslims intend to cause harm, leading to death for the other. Any weapon such as, a sword, rifle, rock, etc. that is used intentionally to cause damage to another Muslim is prohibited in Islam. The reference to two Muslims spells out the nature of the meeting – they both have the intention to do harm to one another. If any Muslims meet with a method by which they can kill, and one of them is successful in killing the other, then both, the killer and the killed shall be in the Hell-fire.
Abu Bakrah (may Allāh be pleased with him) said to the Prophet
, “This is the killer” This type of statement, the repetition of the announcement as a fact, is known in the field of discussion as an agreement to what was said. Allāh says,
“Whoever kills a believer intentionally, his recompense is Hell, he shall abide therein forever. The wrath and the curse of Allāh shall be upon him, and a great punishment is prepared for him” [93, Al-Nisa’a].
what about the one killed?
Upon Abu Bakrah’s questioning about the killed, the Prophet
said, “He was eager to kill his companion” This shows that even though he was killed, this individual will abide in Hell because of his intention and actions. The result, his failure and subsequent death, does not absolve him of the sin. Intention alone, however, is not the only determining factor. The fact that this man brought a means — a weapon, to fulfill his intention is what sealed his fate in Hell. His bringing a weapon shows that he was, “eager to kill his companion.” Success and failure are insignificant because both men are destined for the Hellfire.
This hadith proves that actions are according to their intentions, and that when this man intended to kill his companion, it was as if he actually did kill him. There is, however, a stark difference between these men and martyrs. The Prophet stated, “Whoever is killed protecting himself is a martyr, whoever is killed protecting his family is a martyr, and whoever is killed protecting his wealth is a martyr, [and whoever is killed protecting his deen is a martyr]” [Abu Dawud and at-Tirmidhi]
One who is being attacked and acts in self-defense is not the aggressor; therefore if in the course of defending himself, a man kills an aggressor he is no punished for the act. The Prophet
stated that one who comes to take another’s wealth by force, “If you kill him then he shall be in the Fire, and if he kills you then you are a martyr” [Muslim]
The person who is defending his wealth, family, self and honor is only warding off an aggressor, one who is not repelled except by fighting (him off). If he kills the aggressor, the aggressor shall be in the Fire, and if he is killed in self-defense then he shall be a martyr in Paradise.
Tbh I don't know if this is a fabricated hadith or not but either way there is a quranic verse.
Quran 49:9
And if two parties of the believers quarrel, make peace between them; but if one of them acts wrongfully towards the other, fight that which acts wrongfully until it returns to Allah's command; then if it returns, make peace between them with justice and act equitably; surely Allah loves those who act equitably.
وَإِن طَائِفَتَانِ مِنَ الْمُؤْمِنِينَ اقْتَتَلُوا فَأَصْلِحُوا بَيْنَهُمَا فَإِن بَغَتْ إِحْدَاهُمَا عَلَى الْأُخْرَى فَقَاتِلُوا الَّتِي تَبْغِي حَتَّى تَفِيءَ إِلَى أَمْرِ اللَّهِ فَإِن فَاءتْ فَأَصْلِحُوا بَيْنَهُمَا بِالْعَدْلِ وَأَقْسِطُوا إِنَّ اللَّهَ يُحِبُّ الْمُقْسِطِينَ
Clearly here it's talking about if one if the sides is leaving Allah's command and not about territory since muslims should be living under one state so it's not possible that fighting another muslims over land is legitimate since we should be under one land and pledge allegiance to. 
Funny how 
